THE  LIBRARY 

OF 

THE  UNIVERSITY 

OF  CALIFORNIA 

SANTA  BARBARA 

COLLEGE 


PRESENTED  BY 

Louis  H.  Webb 


M 


THE   PRINCIPLES   OF 
PSYCHOLOGY 


BY 

HERBERT    SPENCER 


VOL.  I 


NEW  YORK 
D.    APPLETON    AND    COMPANY 

1905 


T  -X.  \  SAtrr'-  BARBARA  ^•^. 

t^?l  60517 

PREFACE  TO  THE  THIRD  EDITION. 

This  third  edition  of  the  Principlea  of  Psychology  differs 
from  preceding  editions,  mainly  by  containing  a  new  di- 
vision; which  occurs  in  the  second  volume,  under  the  title 
— "  Part  VIIL,  Congruities." 

By  the  preface  to  the  first  edition,  it  will  be  seen  that  I 
had  originally  intended  to  write,  under  the  title  of  "  Sum- 
mary and  Conclusion,"  a  division  having  for  its  purpose  "  to 
bring  the  several  lines  of  argument  to  a  focus:  "  believing 
that  "  the  harmony  that  may  be  shown  to  subsist  between 
the  doctrines  elaborated  in  the  respective  divisions,  is  a 
strong  confirmation  of  their  truth."  When  I  began  to  pre- 
pare the  second  and  greatly  enlarged  edition,  I  looked  for- 
ward to  fulfilling  this  intention,  which  disturbed  health  had 
before  obliged  me  to  abandon.  Eventually,  however,  I  left 
the  additional  part  unwritten — partly  because  the  work 
had  already  become  too  bulky,  and  partly  because  I  thought 
that  the  harmonies  I  proposed  to  point  out  were  so  con- 
spicuous that  all  readers  would  perceive  them. 

This  last  reason  proved  to  be  ill-grounded.  Far  from  re- 
cognizing the  harmonies  which  I  thought  conspicuous,  sun- 
dry critics  have  enlarged  on  the  incongruities.  In  a  review 
published  in  the  Acadenvy  for  April  1,  18Y3,  Mr.  Henry 
Sidgwick  speaks  of  "  the  mazy  inconsistency  of  his  [my] 
metaphysical  results."  Similarly,  a  writer  in  the  Spectatm' 
for  the  21st  of  June,  1873,  asserts  that  "  Mr.  Spencer's  sys- 
tem has  the  incurable  defect  of  fundamental  incoherence." 
Prof.  Green,  also,  in  two  articles  which  appeared  in  the  Con- 
temporary  Beview  for  December,  1877,  and  March,  1878, 
devotes  much  space  to  showing,  as  he  thinks,  that  my  views 
are  not  coherent.  Thus  I  find  it,  if  not  necessary,  at  any 
rate  desirable,  to  fulfil  my  first  intention. 


Iy  peepacb  to  the  third  edition. 

It  is  a  common  remark  that  where  party  feeling,  political 
or  theological,  runs  high,  one  who,  believing  that  neither 
tide  is  wholly  right  or  wholly  wrong,  declines  to  commit 
himself  entirely  to  either,  is  usually  looked  upon  by  both 
with  suspicion,  if  not  with  aversion.  And  it  is  curious  to 
see  how,  analogously,  in  a  controversy  so  remote  in  its  issuea 
from  human  interests  as  that  between  Realism  and  Idealism, 
the  enunciation  of  a  view  which  recognizes  an  element  of 
truth  in  each,  seems  to  beget  antipathy  rather  than  sympa- 
thy. The  adherents  of  either  doctrine,  believing  that  it  is 
entirely  true  or  entirely  false,  are  averse  to  a  conciliation 
which  requires  any  sacrifice.  Surrender  of  a  part  of  their 
doctrine  is  almost  as  offensive  to  their  amour  propre  as 
surrender  of  the  whole;  and  the  proposer  of  it  is  censured 
all  round. 

Recognizing,  thus,  the  disfavour  with  which  both 
Realists  and  Idealists  naturally  regard  that  Transfigured 
Realism  which  accepts  from  each  a  moiety  of  his  doctrine 
but  rejects  the  rest,  I  scarcely  expect  that  where  they  before 
discovered  only  incongruities,  this  new  division  will  show 
them  that  there  are  congruities.  I  can  do  no  more  than 
exhibit  these,  in  the  belief  that  they  will  be  apparent  to 
all  who  have  not  yet  committed  themselves  to  one  side  or 
the  other.  I  may  add  that  inability  to  recognize  these 
congruities  admits  of  two  interpretations,  conveniently  sug- 
gested by  a  simile  which  I  have  before  employed  in  another 
relation.  Taken  at  different  angles  from  the  same  object, 
the  two  photographs  placed  in  a  stereoscope,  when  first 
viewed,  not  unfrequently  form  a  confused  double  image; 
but  after  persevering  contemplation,  most  observers  find 
them  suddenly  unite  into  a  single  clear  representation  of  the 
object.  Meanwhile,  there  are  some  eyes  which  to  the  last 
fail  in  combining  them;  and  to  which  they  continuously 
appear  conflicting  and  confused. 

LOKDOH,  October,  1880. 


w\\ 


PREFACE  TO  THE  SECOND  EDITION. 


WoEDS  are  somewhat  strained  in  their  meanings  by  calling 
that  a  Second  Edition,  of  which  the  new  portion  greatly  ex- 
ceeds the  old  portion  in  amount;  as  happens  with  this 
volume,  and  as  will  happen  with  its  successor.  Of  the  five 
Parts  here  bound  together,  the  two  that  have  previously  ap- 
peared cover  217  pages;  while  the  three  that  now  appear 
for  the  first  time  cover  425  pages. 

Nevertheless,  the  fact  that  sundry  of  the  cardinal  ideas 
contained  in  this  work  were  enunciated  many  years  ago, 
must  not  be  lost  sight  of.  When,  in  1855,  the  First  Edition 
of  The  Principles  of  Psychology  was  issued,  it  had  to  en- 
counter a  public  opinion  almost  universally  adverse.  The 
Doctrine  of  Evolution  everywhere  implied  in  it,  was  at  that 
time  ridiculed  in  the  world  at  large,  and  frowned  upon  even 
in  the  scientific  world.  Naturally,  therefore,  the  work, 
passed  over,  or  treated  with  but  small  respect,  by  re- 
viewers, received  scarcely  any  attention;  and  its  contents 
remained  unknown  save  to  the  select  few.  The  great  change 
of  attitude  towards  the  Doctrine  of  Evolution  in  general, 
which  has  taken  place  during  the  last  ten  years,  has  made 
the  Doctrine  of  Mental  Evolution  seem  less  unacceptable; 
and  one  result  has  been  that  the  leading  conceptions  set 
forth  in  the  First  Edition  of  this  work,  have  of  late  obtained 
considerable  currency.  In  France,  some  of  them  have  been 
made  known  incidentally  by  the  treatise  of  M.  Taine,  Pe 
r Intelligence;  and  the  lucid  exposition  of  Prof.  Ribot  in 


•vi  PRKPACB  TO  THB  SECOND  BDITIOlf, 

hifl  Psychologie  Anglaise  Contemporatnef  has  presented 
them  all  in  a  systematic  form.  In  England,  they  have 
spread  through  various  channels.  Among  these  I  may  more 
especially  name  The  Physiology  and  Pathology  of  the 
Mindy  by  Dr.  Maudsley,  the  first  division  of  which  work  is 
pervaded  by  them.  As  most  of  those  who  will  read  this 
Second  Edition  of  the  Principles  of  Psychology y  never  saw 
the  First  Edition,  and  cannot  now  get  access  to  it;  and  as, 
in  Parts  m.  and  IV.,  they  will  meet  with  ideas  that  have 
been  already  made,  in  the  ways  indicated,  more  or  less  fa- 
miliar to  them;  it  is  needful  that  I  should  state  these  facta 
to  prevent  misapprehensions. 

Part  v.,  which  closes  this  volume,  is  the  Part  referred  to 
in  the  final  paragraph  of  the  Preface  to  the  First  Edition, 
as  omitted  for  the  reasons  given.  In  now  fulfilling  the  half- 
promise  there  made,  eventually  to  add  it  to  the  rest,  I  have 
the  satisfaction  of  feeling  that  during  the  fifteen  years  that 
have  elapsed,  the  hypothesis  set  forth  in  it  has  assumed  a 
much  higher  development. 

The  long  delays  in  the  issues  of  the  successive  portions  of 
this  work,  have  arisen  in  part  from  disturbances  of  health 
that  have  from  time  to  time  compelled  me  to  desist  from 
work,  and  in  part  from  the  continuous  attention  taken  in 
arranging  and  superintending  a  systematic  collection  of 
materials  for  the  Principles  of  Sociology ^  presently  to  be 
commenced.  I  have  reason  to  hope  that  neither  of  these 
causes  will  operate  so  seriously  in  delaying  the  issue  of  the 
numbers  which  are  to  compose  the  second  volume. 

Lomwv,  Dutniber,  1870. 


PREFACE. 


The  four  parts  of  which  this  work  consists,*  though  inti- 
mately related  to  each  other  as  different  views  of  the  same 
great  aggregate  of  phenomena,  are  yet,  in  the  main,  severally 
independent  and  complete  in  themselves.  The  particular 
serial  arrangement  in  which  they  should  be  presented,  has 
consequently  been  in  great  measure  a  question  of  general 
expediency;  and  while  the  order  I  have  chosen  is  one 
which  seems,  on  the  whole,  the  most  advantageous,  it  is 
not  one  which  all  readers  are  bound  to  follow.  A  brief 
characterization  of  each  part,  will  enable  every  one  to  de- 
cide for  himself  which  he  may  best  commence  with.f 

The  General  Analysis  (of  which  the  essential  portion  was 
originally  published  in  the  Westminster  JReview  for  Octo- 
ber, 1853,  under  the  title  of  "  The  Universal  Postulate," 
and  reappears  here  with  additional  arguments  and  explana- 
tions) is  an  inquiry  concerning  the  basis  of  our  intelligence. 
Its  object  is  to  ascertain  the  fundamental  peculiarity  of  all 
modes  of  consciousness  constituting  knowledge  proper — 
knowledge  of  the  highest  validity. 

The  Special  Analysis  has  for  its  aim,  to  resolve  each 
apecies  of  cognition  into  its  components.  Commencing  with 
the  most  involved  ones,  it  seeks  by  successive  decomposi- 

*  The  number  of  parts  is  now  greatly  increased :  this  Tolume  contains 
fire,  and  the  second  volume  will  contain  four. 

f  The  order  has  now  been  wholly  changed :  the  two  parts  immediately 
named  as  coming  first,  being  relegated  to  the  second  rolums. 

rii 


viii  PREFACE. 

tions  to  reduce  cognitions  of  every  order  to  those  of  the 
simplest  kind;  and  so,  finally  to  make  apparent  the  com- 
mon nature  of  all  thought,  and  disclose  its  ultimate  con- 
stituents. 

While  these  analytical  parts  deal  with  the  phenomena  of 
intelligence  subjectively,  and,  as  a  necessary  consequence, 
are  confined  to  human  intelligence;  the  synthetical  parts 
deal  with  the  phenomena  of  intelligence  objectively,  and  so 
include  not  human  intelligence  only,  but  intelligence  under 
every  form. 

The  General  Synthesis,  setting  out  with  an  abstract  state- 
ment of  the  relation  subsisting  between  every  living  organ- 
ism and  the  external  world,  and  arguing  that  all  vital 
actions  whatever,  mental  and  bodily,  must  be  expressible 
in  terms  of  this  relation;  proceeds  to  formulate,  in  such 
terms,  the  successive  phases  of  progressing  Life,  considered 
apart  from  our  conventional  classifications  of  them.* 

And  the  Special  Synthesis,  after  exhibiting  that  gradual 
differentiation  of  the  psychical  from  the  physical  life  which 
accompanies  the  evolution  of  Life  in  general,  goes  on  to  de- 
velop, in  its  application  to  psychical  life  in  particular,  the 
doctrine  which  the  previous  part  sets  forth:  describing  the 
nature  and  genesis  of  the  different  modes  of  Intelligence,  in 
terms  of  the  relation  which  obtains  between  inner  and  outer 
phenomena. 

As  may  be  supposed,  the  analytical  divisions  are  much 
less  readable  than  the  synthetical  ones.  Hence,  while  all 
who  are  accustomed  to  studies  of  an  abstract  character  are 
recommended  to  follow  the  order  in  which  the  parts  stand, 
as  being  that  most  conducive  to  a  clear  understanding  of 
the  system  in  its  ensemble;  those  who  are  unfamiliar  with 
mental  philosophy  may,  perhaps,  more  advantageously 
begin  with  Parts  III.  and  IV. :  returning  to  Parts  I.  and  II. 
should  they  feel  sufficiently  interested  to  do  so. 

*  A  portion  of  the  Part  thus  described,  is  now  embodied  in  Th4  iVt'n- 
eiples  of  Biology. 


PREFACE,  ix 

Kespecting  the  execution  of  the  work,  I  may  say  that  in 
sundry  ways  it  falls  much  short  of  my  wishes.  There  arc 
places  in  which  the  argument  is  incompletely  carried  out; 
places  in  which,  from  inadequate  explanation,  there  is  an 
apparent  incongruity  between  the  statements  there  made 
and  those  made  elsewhere;  and  there  are,  I  fear,  places 
where  the  form  of  expression  is  not  so  precise  as  it  should  be. 
Add  to  which,  that  in  treating  under  several  separate  aspects 
a  subject  so  extensive,  I  have  perhaps  erred  in  attempting 
too  much;  and  have  so  devoted  neither  thought  enough 
nor  space  enough  to  any  one  of  the  several  aspects  under 
which  the  subject  is  presented. 

While,  however,  I  am  conscious  that  the  work  contains 
many  more  imperfections  than  it  would  have  done  had  its 
scope  been  more  limited  and  its  elaboration  longer,  I  would 
excuse  the  issue  of  it  in  its  present  form  on  several  grounds: 
partly  on  the  ground  that  it  is  almost  useless  to  wait  until 
any  organized  body  of  thought  has  reached  its  full  develop- 
ment, which  it  never  does  in  the  course  of  a  single  life; 
partly  on  the  ground  that  it  is  next  to  impossible  for  the 
writer  of  a  work  like  this,  to  dispense  with  the  aid  of  can- 
did criticism;  but  chiefly  on  the  ground  that  the  general 
truths  enunciated,  being,  as  I  believe,  both  new  and  im- 
portant, it  seemed  to  me  undesirable  to  delay  their  publica- 
tion with  the  view  of  by  and  by  presenting  them  in  a  more 
finished  guise. 

For  the  somewhat  abrupt  termination  of  the  work,  my 
apology  must  be,  that  disturbed  health  has  obliged  me  to 
desist  from  writing  a  "  Summary  and  Conclusion,"  in  which 
I  purposed  to  bring  the  several  lines  of  argument  to  a 
focus.  I  greatly  regret  this ;  not  only  because  the  harmony 
that  may  be  shown  to  subsist  between  the  doctrines  elabor- 
ated in  the  respective  divisions,  is  a  string  confirmation 
of  their  truth ;  but  because,  in  the  absence  of  explanation, 
some  misunderstanding  may  arise  concerning  the  implica- 


X  PREFACE. 

tions — ontological  and  other — which  many  will  think  mani- 
fest. 

It  may  be  well  further  to  say  that,  originally,  I  had  in- 
tended to  add  a  fifth  division,  which  should  include  sundry 
deductions  and  speculations  that  could  not  properly  be  em- 
bodied in  the  other  divisions.  But  before  being  compelled 
to  do  so,  I  had  decided,  that  as  this  fifth  division  was  not 
strictly  necessary;  and  as  certain  of  the  suggestions  con- 
tained in  it  might  prejudice  some  against  the  doctrines  de- 
veloped in  the  others;  it  would  be  better  to  withhold  it- — 
at  any  rate  for  the  present 

Jviy,  1856. 


CONTENTS  OF  YOl.  I. 


PART  I.— THE  DATA  OF  PSTCHOLOGT. 

CHAP.  FAOB 

I. THE   NERVOUS    SYSTEM 3 

II. THE    STRUCTURE   OF   THE   NERVOUS    SYSTEM.            .  15 

in. THE   FUNCTIONS   OF   THE   NERVOUS    SYSTEM  .            .  4:6 

lY.— THE   CONDITIONS   ESSENTIAL   TO   NERVOUS    ACTION  68 

V. — NERVOUS  STIMULATION   AND   NERVOUS  DISCHARGE  79 

VI. ^STHO-PHYSIOLOGY     ......  97 

VII. — THE   SCOPE   OF   PSYCHOLOGY           ....  129 

PART  II.— THE  INDUCTIONS  OF  PSYCHOLOGY. 

I. — THE    SUBSTANCE   OE   MIND   .            .            .            .            .  145 

II. — THE   COMPOSITION    OF   MIND            ....  163 

III. THE   RELATIVITY   OF   FEELINGS    ....  193 

IV. — THE   RELATIVITY   OF   RELATIONS   BETWEEN   FEEL- 
INGS                ...  210 

V. THE   REVIVABILITY   OF   FEELINGS           .            .            .  228 

VI. — THE     REVIVABILITY     OF      RELATIONS      BETWEEN 

FEELINGS 240 

Vn. ^THE   A8S0CIABILITY   OF   FEELINGS           .            .            .  250 

Vin. THE  ASSOCIABILITY  OF  RELATIONS  BETWEEN  FEEL- 
INGS     259 

IX. — PLEASURES   AND   PAINS 272 

PAET  III.— GENERAL  SYNTHESIS. 

I. — LIFE  AND  MIND  AS  CORRESPONDENCE     .     .  291 
II. — THE  CORRESPONDENCE  AS  DIRECT  AND  HOMOGE- 
NEOUS       295 

HI. THE  CORRESPONDENCE  AS  DIRECT  BUT  HETERO- 
GENEOUS        .     .  300 

IV. — THE  CORRESPONDENCE  AS  EXTENDING  IN  SPACE  .  304 

V. — ^THB  CORRESPONDENCE  AS  EXTENDING  IN  TIMS  .  320 


xu 


CONTENTS. 


VI. — THE  OOBBESPONDENCB  AS   mCBEASING   IN   8PECI- 

ALITT              .......  329 

Vn. — THE   CX)BBE8P0in)ENCK   AS    INCKEA8ING    IN   GENE- 

BALITT          .......  342 

Vin. THE    C50KBE8PONDENCE    AS    INCBEA8ING     IN    COM- 
PLEXITY          350 

H. — THE  CX)-OBDINATION   OF  OOEKE8PONDENCE8 .            .  370 

X. — THE   INTEGKATION   OF   CX)BBESPONDEN0ES      .            .  377 

XI. — THE   COBEE8PONDENCES    IN    THEIB   TOTALITT           .  385 

PART  IV.— SPECIAL  SYNTHESIS. 

I. — THE  NATUBE  OF  INTELLIGENCE.     .     .     .  395 

n. — THE  LAW  OF  INTELLIGENCE    ....  407 
in. — THE  GBOWTH  OF  INTELLIGENCE      .     .     .418 

IV. — BEFLEX  ACTION 427 

V. — INSTINCT 432 

VI. — MEMOBT 444 

vn. — BEA80N 453 

Vni. — THE  FEELINGS 472 

IX. — THE  WILL 495 

PART  v.— PHYSICAL  SYNTHESIS. 

I. A   FDBTHEB    INTEBPBETATION   NEEDED            .            .  507 

n. ^THE   GENESIS   OF   NEBVES 511 

in. — THE   GENESIS   OF   SIMPLE   NEBVOUS   SYSTEMS            .  521 

IV. — THE   GENESIS    OF   COMPOUND    NEBVOUS    SYSTEMS    .  532 
V. — ^IHE     GENESIS     OF     DOUBLY-COMPOUND     NEBVOUS 

SYSTEMS 542 

VI. — FUNCTIONS    AS   BELATED   TO   THESE    STBUCTUBES  .  559 

vn. — PSYCHICAL   LAWS   AS   THUS    INTEEPBETED     .            .  577 

Vin. — EVIDENCE   FBOM    NOBMAL   VABIATIONS            .            .  585 

H. — EVIDENCE   FBOM   ABNOBMAL   VABIATIONS      .            .  604 

X. — BK8ULT8 614 

APPENDIX. 

OK   THE   ACTIONS   OF   ANESTHETICS    AND   NABCOTICS          .  629 

CONSCIOUSNESS   UNDSB  OHLOBOFOBM       ....  636 


PART   I. 


IHE   DATA   OF  PSYCHOLOGY. 


CHAPTER  I. 


THE    NERVOUS    SYSTEM. 


§  1.  The  lowest  animal  and  the  highest  animal  present 
no  contrast  more  striking  than  that  between  the  small  self- 
mobility  of  the  one  and  the  great  self -mobility  of  the  other. 
A  monad  passing,  apparently  with  some  rapidity,  across  the 
field  of  the  microscope,  really  advances  with  extreme  slow- 
ness: its  velocity,  unexaggerated  by  combined  lenses, 
being  about  that  of  the  minute-hand  of  a  watch.  The  parts 
of  a  disturbed  sea-anemone  draw  themselves  together  with 
a  speed  which,  though  immensely  greater  than  that  of  a 
monad  through  the  water,  is  insignificant  as  measured  by 
the  speed  of  most  terrestrial  and  aerial  creatures.  Compar- 
ing the  movements  of  Protozoa^  or  of  Zoophytes^  with  those 
of  Birds  that  keep  pace  with  railway  trains  or  those  Mam- 
mals that  gallop  a  mile  in  a  minute,  their  locomotive  powers 
seem  scarcely  appreciable.  Masses  being  supposed  equal, 
the  quantity  of  motion  generated  in  the  last  case  approaches 
a  million  times  that  generated  in  the  first. 

Contrasts  of  this  kind  exist  within  each  great  division  of 
the  animal  kingdom,  as  well  as  in  the  animal  kingdom 
taken  as  a  whole.  The  sub-kingdom ^wri-wZos^  shows  us  an 
immense  diflFerence  between  the  slow  crawling  of  worms 
and  quick  flight  of  insects.  Among  Mollusks  the  sluggish- 
ness of  the  Tunicata  is  no  less  marked  than  the  activity  of 
the  Cephalopoda.  And  between  the  inferior  or  water- 
2  8 


4  THE  DATA  OF  PSYCHOLOGY. 

breathing  Yertetyrata  and  superior  or  air-breathing  Yerte- 
hrata^  there  is  an  equally  conspicuous  unlikeness  in  energy 
of  movement. 

This  self-mobility  which  by  its  greater  amount  generally 
distinguishes  higher  animals  from  lower,  and,  indeed,  enters 
largely  into  our  conceptions  of  higher  and  lower,  is  displayed 
in  several  ways.  We  see  it  in  the  changes  of  attitude  that 
are  made  without  moving  the  body  from  place  to  place. 
We  see  it  in  the  transference  of  the  body  as  a  whole 
through  space:  considering  this  transference  apart  from 
external  resistances  overcome.  And  we  see  it  in  the  over- 
coming of  resistances — both  those  of  media  and  those 
due  to  gravity.  All  these,  however,  are  manifestations  of 
one  ability — the  ability  to  generate  a  force  which  either 
shows  itself  as  momentum  or  would  generate  momentum 
but  for  a  counterbalancing  force.  And  it  is  in  this  general 
form  that  we  are  here  concerned  with  this  ability.  We  have 
to  contemplate  the  inferior  animals  as  being  generators  of 
very  small  quantities  of  actual  or  potential  motion,  and  the 
higher  animals  as  being  generators  of  relatively-immense 
quantities  of  actual  or  potential  motion. 

§  2.  With  what  internal  differences  are  these  differences 
of  external  manifestation  connected?  No  doubt  with  sev- 
eral. An  active  organism  contains  various  appliances  no 
one  of  which  can  be  spared  without  greatly  diminishing, 
or  quite  destroying,  its  activity. 

If  the  alimentary  system  be  incapacitated,  there  must  pre- 
sently result  a  decreased  power  of  generating  motion,  from 
lack  of  the  materials  whence  motion  is  obtained ;  and  hence 
the  fact,  conspicuous  throughout  the  animal  kingdom,  that 
along  with  much  locomotive  activity  there  goes  a  developed 
apparatus  for  taking  up  nutriment.  It  is  manifest,  too, 
that  there  cannot  be  great  self-mobility  unless  the  absorbed 
materials  are  efficiently  distributed  to  the  organs  which 
transform  insensible  motion  into  sensible  motion;  and  thus 


THE  NERVOUS  SYSTEM.  ^ 

it  happens  that  as  we  ascend  from  creatures  which  move 
little  to  creatures  which  move  much,  we  meet  with  a  more 
and  more  evolved  vascular  system.  Similarly  with  the 
organs  for  separating  from  the  blood  the  substances  that 
have  yielded  up  their  contained  motion.  If  the  blood  be- 
comes choked  with  inert  matter,  there  necessarily  results  a 
decreased  genesis  of  motion;  and  therefore,  as  we  see  on 
comparing  inactive  with  active  animals,  the  exaltation  of 
activity  is  accompanied  by  the  development  of  depurating 
structures.  Still  clearer  is  it  that  the  production  of  much 
motion,  and  the  resistance  to  those  forces  which  antagonize 
motion,  imply  parts  capable  of  bearing  great  strains — 
masses  of  dense  tissue  such  as  in  vertebrate  animals  form 
bones,  and  in  invertebrate  animals  form  dermal  frame- 
works; and,  accordingly,  as  we  ascend  from  creatures  that 
are  inert  to  creatures  that  are  vivacious,  we  advance  from 
weak  to  strong  skeletons,  internal  or  external.  Above  all 
it  is  self-evident  that  along  with  locomotive  activity  there 
must  exist  those  contractile  organs  which  are  the  imme- 
diate movers  of  the  limbs  and  consequently  of  the  body; 
and  hence  the  direct  connection  between  absence  of  mus- 
cular fibres  and  extremely-small  self -mobility,  and  the  direct 
connection  between  development  of  the  muscles  and  much 
self-mobility — connections  so  direct  as  to  make  it  at  first 
sight  seem  that  the  genesis  of  motion  varies  as  the  mus- 
cular development. 

Remotely  dependent,  however,  as  the  genesis  of  motion 
is  on  digestive,  vascular,  respiratory,  and  other  structures; 
and  immediately  dependent  as  it  is  on  contractile  struc- 
tures ;  its  most  important  dependence  remains  to  be  named. 
For  all  of  these  appliances  taken  together  can  do  nothing 
of  themselves.  The  muscles  are  but  instruments,  which 
remain  passive  until  their  power  is  evoked  by  the  structure 
which  uses  them;  and  the  quantity  of  motion  they  then 
give  out  varies  according  to  the  demand  made  by  this- 
exciting  and  controlling  structure.     In  other  words,  the 


^  THE  DATA  OF  PSYCHOLOGY. 

initiator  or  primary  generator  of  motion  is  the  IN'ervoua 
System.  Where  there  is  extremely  little  power  of  generat- 
ing motion,  as  among  the  Protozoa  and  the  inferior  Coslen- 
terata,  there  is  no  nervous  system.  Where  activity  begins 
to  show  itself  a  nervous  system  begins  to  be  visible.  And 
where  the  power  of  self-movement  is  great,  the  nervous 
system  is  comparatively  well  developed.  Though  the  mus- 
cular system  also  becomes  larger  and  better  organized;  yet 
the  quantity  of  motion  produced  is  fundamentally  related  to 
the  degree  of  nervous  development.  Not,  indeed,  that  it  is 
so  related  with  anything  like  uniformity:  this  we  shall 
presently  see  that  it  cannot  be.  But  it  is  so  related  more 
uniformly  than  in  any  other  way.  A  few  typical  contrasts 
will  show  this. 

§  3.  The  absence  of  measurements  renders  detailed  com- 
parison among  the  various  classes  of  MoUusca  unsatisfac- 
tory. On  putting  side  by  side  the  extreme  terms,  however, 
we  find  an  unquestionable  difference  in  the  proportion  be- 
tween the  nervous  system  and  the  rest  of  the  body.  The 
sedentary  Ascidians,  which  do  little  in  the  way  of  moving 
beyond  occasionally  contracting  themselves,  severally  pos- 
sess only  a  single  small  ganglion  with  its  fibres;  but  Cepha- 
lopods  of  the  dibranchiate  order,  which  are  active  creatures 
that  dart  through  the  water  fast  enough  to  catch  fish,  con- 
tain masses  of  nerve-tissue  that  bear  much  larger  ratios  to 
their  total  masses. 

It  is  with  annulose  animals  as  with  molluscous  animals — 
we  have  no  definite  estimates  of  the  sizes  of  their  nervous 
systems;  and  hence  can  bring  in  evidence  only  the  marked 
diflFerences.  As  before,  the  extreme  forms  supply  these. 
The  sluggish  annuloid  types,  when  contrasted  with  the 
energetic  kinds  of  Annvlosa^  present  decided  deficiencies  of 
nerve-substance;  and  even  between  such  less-remote  orders 
as  the  tubicolous  Annelids,  leading  stationary  lives,  and  the 
decapodous  Crustaceans,  leading  active  lives,  a  kindred 


THE  NERVOUS  SYSTEM.  7 

difference  may  be  safely  asserted.  There  are  also,  in  some 
annulose  types  contrasts  between  the  nervous  system  in  the 
inactive  and  active  stages  of  the  same  individual.  The  feebly- 
moving  caterpillar  has  but  a  small  nervous  system;  the 
butterfly,  with  its  power  of  vigorous  flight,  has  a  relatively 
large  one ;  and  during  the  intermediate  pupa-state,  in  which 
the  organization  is  being  adapted  to  this  more  vivacious 
life,  a  rapid  growth  of  the  nervous  system  may  be  traced. 

It  is  in  the  Vertebrata,  however,  that  the  most  striking 
evidence  meets  us.  According  to  Leuret,  the  average  ratio 
of  the  brain  to  the  body  is — in  fishes,  1  to  5,668;  in  rep- 
tiles, 1  to  1,321;  in  birds,  1  to  212;  and  in  mammals,  1  to 
186.  ]^ow  though  these  can  be  but  rude  approximations, 
since  there  are  great  differences  within  each  class,  and  since 
the  ratio  of  the  brain  to  the  body  is  not  the  ratio  of  the 
whole  nervous  system,  to  the  body;  yet  the  relations  they 
indicate  are  substantially  true.  Were  the  weight  of  the 
spinal  cord  and  the  nerves  added  to  that  of  the  brain  in 
each  case,  the  strengths  of  the  contrasts  would  be  consider- 
ably diminished;  but  the  contrasts  would  still  be  strong. 
And  with  them  there  go  the  strong  contrasts  between  the 
activities  in  the  respective  classes — the  Fishes  that  swim  jn 
a  medium  of  their  own  specific  gravity;  the  Reptiles  of 
which  the  higher  have  to  support  the  weights  of  their 
bodies  as  they  move  about  over  the  land,  but  cannot  do 
this  for  long  together;  the  Birds  and  Mammals  that  are  in 
constant  locomotion,  often  at  high  velocities.  Here, 

too,  the  alleged  connection  is  rendered  the  clearer  by  the 
approximate  uniformity  of  the  relative  amount  of  muscle. 
The  weight  of  muscle  in  a  fish  forms  something  like  as 
large  a  part  of  the  total  weight  as  it  does  in  a  reptile — 
perhaps  a  larger  part;  and  a  reptile  is  scarcely  if  at  all 
inferior  to  a  bird  or  a  mammal  in  the  proportion  of  contrac- 
tile tissue  it  possesses.  Hence  it  becomes  manifest  that 
indispensable  as  is  contractile  tissue  to  the  genesis  of  mo- 
tion, its  quantity  does  not  determine  the  quantity  of  motion 


8  THE  DATA  OF  PSYCHOLOGY. 

generated.  Whereas,  notwithstanding  the  many  complicat- 
ing circumstances,  a  general  relation  between  quantity  of 
nerve  and  quantity  of  motion  is  traceable. 

There  are  special  cases  which  illustrate  this  relation.  I 
may  name  one — the  case  of  the  Porpoise.  A  Porpoise's 
brain  exceeds  greatly  in  size  the  brains  of  other  Mammals 
that  have  bodies  commensurate  with  its  own,  except 
that  of  Man  and,  perhaps,  that  of  the  Gorilla.  Such  a 
structure  in  a  creature  leading  so  simple  a  life,  is  a  serious 
difficulty  in  the  way  of  current  interpretations;  but  is  quite 
in  harmony  with  the  interpretations  here  given.  Porpoises 
accompanying  a  steam-vessel,  gambolling  and  making  ex- 
cursions on  either  side  without  apparent  effort,  prove,  by 
keeping  up  so  high  a  velocity  through  so  dense  a  medium, 
that  their  motor  energies  are  enormous. 

§  4.  A  closer  examination  of  the  facts  soon  reveals  the 
insufficiency  of  the  foregoing  generalization.  Deep  as  is 
the  connection  between  nervous  development  and  locomotive 
activity,  further  comparisons  show  that  it  is  complicated 
with  some  other  connection  scarcely  less  radical.  If,  other 
things  being  equal,  the  quantity  of  motion  generated 
varied  directly  as  the  quantity  of  nerve-tissue,  then,  in 
creatures  constitutionally  alike  or  but  little  dissimilar,  a 
tolerably  constant  ratio  would  exist  between  the  mass  of 
the  nervous  system  and  the  mass  of  the  body:  supposing 
the  body,  whether  large  or  small,  to  be  carried  from  place 
to  place  with  equal  velocity.  The  ratio  is  far  from  constant 
however. 

A  horse  gallops  much  faster  than  a  man  runs;  and  a 
horse  in  ordinary  work  daily  moves  his  body  through  a 
space  greater  than  that  through  which  a  man  moves  his  body, 
or  greater  than  that  transposition  of  his  body  which  a  man's 
daily  labour  is  equivalent  to.  Hence  were  there  a  simple 
relation  between  amount  of  nerve-tissue  and  amount  of  mo- 
tion evolved,  a  horse,  which  weighs  some  seven  times  as  much 


THE  NERVOUS  SYSTEM.  9 

as  a  man,  should  have  a  nervous  system  at  least  seven  times 
as  heavy.  Instead  of  this  it  has  a  lighter  nervous  system.  Its 
brain  weighs  but  one  pound  seven  ounces ;  and  were  its  spinal 
cord  added,  the  total  weight  would  probably  not  exceed  two 
pounds.  But  a  man's  brain  and  spinal  cord  weigh  between 
three  and  four  pounds.  Thus  the  horse's  cerebro-spinal 
axis  is  but  one-tenth  of  what  it  should  be,  were  this  relation 
the  only  one.  Still  clearer  is  the  proof  that  there 

is  some  other  relation,  when  we  avoid  modifying  causes,  by 
comparing  animals  of  the  same  genus,  or  species,  but  of 
different  sizes.  The  varieties  of  dogs  supply  good  illustra- 
tions. A  newf  oundland  and  a  spaniel  are  alike  in  organiza- 
tion, food,  temperature,  respiration,  &c. ;  and  they  are 
approximately  alike  in  their  powers  of  locomotion:  the 
advantage  being  on  the  side  of  the  larger  of  the  two. 
Were  genesis  of  motion  measured  by  quantity  of  nerve- 
tissue,  a  newfoundland's  cerebro-spinal  axis  should,  there- 
fore, exceed  in  size  that  of  a  spaniel  as  much  as  a  newfound- 
land's  body  exceeds  in  size  that  of  a  spaniel.  But  it  by  no 
means  does  so.  While  considerably  larger  absolutely,  it  is 
much  smaller  relatively. 

Consequently,  we  must  say  that  though  the  nervous 
system  is  the  initiator  of  motion,  and  though  there  is  evi- 
dently some  relation  between  degree  of  nervous  develop- 
ment and  degree  of  motor  energy;  yet  this  relation  is 
involved  with,  and  obscured  by,  another.  Let  us  re-examine 
the  facts  in  search  of  it. 

§  5.  In  what  other  way  than  in  relative  feebleness,  do  the 
motions  of  inferior  creatures  differ  from  those  of  superior 
creatures?  They  differ  in  relative  simplicity.  Animals 
that  are  but  little  evolved  perform  actions  which,  besides 
being  slow,  are  few  in  kind  and  severally  uniform  in  com- 
position. Animals  that  are  much  evolved  perform  actions 
which,  besides  being  rapid,  are  numerous  in  kind  and  sever- 
ally involved  in  composition.     The  movements  in  the  one 


10  THE  DATA  OP  PSYCHOLOGY. 

case  are  small  and  homogeneous,  and  in  the  other  case 
great  and  heterogeneous.  Each  sub-kingdom  of  animals 
exemplifies  this  second  general  relation,  as  much  as  it  does 
the  first. 

Humble  Mollusks,  like  the  fixed  TVwwja^a,  display  scarcely 
any  energies  beyond  those  required  to  contract  their  bodies 
when  disturbed  and  afterwards  to  unfold  them.  But  in  the 
highly-organized  Cuttle-fishes,  besides  the  rapid,  quickly- 
varied,  and  well-adjusted  movements  exhibited  in  the  pur- 
suit and  capture  of  prey,  we  have  the  numerous  and  com- 
bined movements  of  the  suckered  arms,  used  not  only  for  pre- 
hension but  occasionally  for  travelling  over  solid  surfaces. 

The  Annvlosa,  including  with  them  the  Annuloida,  sup- 
ply a  like  general  contrast.  Between  the  uniform,  little- 
varied  motions  of  a  Nemertine  worm,  and  the  multiform, 
variously-combined  motions  of  the  Crab  or  the  Spider,  the 
difference  is  paralleled  by  the  difference  in  nervous  evolu- 
tion. And  a  like  structural  contrast  accompanies  the  con- 
trast between  the  few  simple  actions  of  the  caterpillar  and 
the  numerous  complex  actions  of  the  butterfly. 

But  that  heterogeneity  of  movement  increases  along  with 
relative  size  of  the  nervous  system,  is  best  shown  by  com- 
parisons among  vertebrate  animals.  Progressing  by  alter- 
nate contractions  of  its  lateral  muscles,  and  opening  its 
jaws  to  take  in  food  and  water,  the  Fish  adds  to  these  little 
else  but  those  undulations  of  the  fins  and  tail  that  serve  to 
balance  and  turn  it.  A  Reptile,  using  its  limbs  in  the  water 
or  on  land  or  both,  performs  muscular  actions  considerably 
more  varied  and  more  combined ;  but  still,  actions  that  are 
directed  to  comparatively  few  ends.  An  ordinary  Mammal 
exhibits  in  the  chase  and  destruction  of  prey,  in  the  making 
of  burrows,  in  the  rearing  of  young,  in  the  laying  up  of 
food,  a  greater  variety  of  actions  that  are  severally  more 
compound.  On  arriving  at  the  higher  Mammals,  ending  with 
Man,  we  meet  with  motions  that  are  almost  countless  in 
their  kinds^  that  are  severally  composed  of  many  minor 


THE  NERVOUS  SYSTEM.  1] 

motions  accurately  adjusted  in  their  relative  quantities  and 
successions,  and  that  are  themselves  compounded  into 
courses  of  action  directed  to  multiform  objects.  And  with 
each  such  increment  of  complexity  in  the  motor  functions 
throughout  the  Yertebrata^  there  goes  an  increment  of 
nervous  endowment. 

This,  then,  is  the  secondary  connection  which  traverses 
and  complicates  the  primary  connection.  We  saw  that  were 
there  no  other  relation  than  that  between  quantity  of 
nerve-tissue  and  quantity  of  motion  generated,  a  Horse 
should  have  a  far  larger  nervous  system  than  a  Man, 
instead  of  having  a  smaller  one.  But  finding  that  there 
is  also  a  relation  between  quantity  of  nerve^tissue  and 
complexity  of  motion,  we  are  led  to  expect  an  excep- 
tionally large  nervous  system  in  Man;  and  are  enabled  to 
understand  why  he  has  a  larger  one  than  a  Horse  has.  More 
obvious,  because  not  involved  with  irrelevant  differences,  is 
the  interpretation  thus  yielded  of  the  general  rule,  already 
illustrated  in  the  case  of  the  Dogs,  that  in  each  natural 
group  or  order  of  Mammals,  the  nervous  systems  do  not  in- 
crease in  the  same  ratio  as  the  bodies.  We  will  glance  at 
another  illustration  of  this,  supplied  by  the  Primates :  spe- 
cially instructive  because  of  the  significant  exception  it  con- 
tains, and  specially  interesting  because  that  exception  is 
furnished  by  mankind. 

The  small  monkeys  have  relatively  very  large  brains — 
larger  relatively  than  the  brains  of  their  congeners,  in- 
cluding even  the  highest.  This  connection,  parallel  to  that 
presented  in  the  spaniel  and  the  newf  oundland,  has  a  parallel 
explanation.  The  movements  of  the  little  Capuchin  monkey 
are  approximately  as  varied  and  complex  as  those  of  the 
great  Gorilla;  and  hence,  in  so  far  as  nervous  evolution  is 
related  to  heterogeneity  of  motion,  the  Capuchin  should  have 
a  nervous  system  differing  but  little  in  size  from  that  of  the 
Gorilla.  But  since  there  is  also  a  relation  between  quantity 
of  nerve  and  quantity  of  motion  generated,  the  Gorilla's 


j2  THE  DATA  OF  PSYCHOLOGY. 

nervous  system  must  be  absolutely  greater  though  relatively 
smaller:  which  we  find  it  to  be.  Between  the  Gorilla  and 
Man,  however,  there  exists  a  converse  contrast.  Heavier 
than  a  Man,  and  moving  about  in  the  trees,  a  Gorilla  pro- 
bably generates  daily  as  much  motion  as  a  savage,  or  as  a 
civilized  labourer;  and  were  it  the  sole  function  of  nerve- 
tissue  to  originate  motion,  should  have  at  least  as  large  a 
nervous  system.  But  the  nervous  system  of  Man  is  twice 
as  heavy.  Here,  therefore,  all  other  relations  being  sub- 
stantially the  same,  and  the  physiological  processes  being 
approximately  alike  in  the  two  cases,  the  relative  largeness 
of  the  human  nervous  system  stands  clearly  related  to  the 
relatively-enormous  complexity  of  human  actions — a  com- 
plexity shown  partly  in  the  more  compound  simultaneous 
movements,  but  mainly  in  the  combination  of  successive 
movements,  simple  and  compound,  directed  to  remote 
ends. 

§  6.  This  double  relation  must  still  be  taken  as  ap- 
proximate only.  Seeing  as  we  did  at  the  outset  that  the 
genesis  of  motion  depends  on  many  physiological  conditions, 
of  which  each  is  separately  variable,  it  is  manifest  that 
the  fundamental  connections  we  have  traced  must  have 
sundry  minor  irregularities.  Without  treating  of  these  in 
detail,  it  may  be  well  to  instance  one — that  due  to  differ- 
ence of  bodily  temperature.  Birds  as  a  class  are  more 
active  than  Mammals  as  a  class;  and  though  many  Mammals 
go  through  motions  more  heterogeneous  than  those  of  Birds, 
yet  the  inferior  Mammals  can  scarcely  be  said  to  exceed 
Birds  in  the  heterogeneity  of  their  motions.  Nevertheless, 
the  nervous  systems  of  Birds  are  relatively  somewhat 
smaller  than  the  nervous  systems  of  Mammals.  The  explana- 
tion is  that  Birds  have  a  higher  blood-heat  with  its  accom- 
panying more  active  respiration — both  implying  a  greater 
rate  of  molecular  change.  And  a  greater  rate  of  molecular 
change  enables  a  smaller  nervous  system  to  generate  an 


THE  NERVOUS  SYSTEM.  13 

amount  of  motion  which  would  require  a  larger  nervous 
system  if  the  rate  of  molecular  change  were  less. 

A  further  qualifying  fact  to  be  here  named  is  that,  all 
other  things  being  equal,  the  power  of  a  nervous  system 
does  not  vary  exactly  as  its  mass.  For  reasons  that  will 
hereafter  appear,  its  efficiency  as  a  motor  agent  increases 
in  a  somewhat  higher  ratio  than  the  quantity  of  matter  it 
contains. 

But  after  all  modifying  causes  have  been  allowed  for, 
there  remain  substantially  intact  the  fundamental  rela- 
tions set  forth — namely,  that  wherever  much  motion  is 
evolved,  a  relatively-large  nervous  system  exists;  that 
wherever  the  motion  evolved  though  not  great  in  quantity 
is  heterogeneous  in  kind,  a  relatively-large  nervous  system 
exists ;  and  that  wherever  the  evolved  motion  is  both  great 
in  quantity  and  heterogeneous  in  kind,  the  largest  nervous 
systems  exist. 

§  7.  It  is  with  deliberate  intention  that  I  have  set  out 
with  this  unfamiliar  and,  as  many  will  think,  somewhat 
strange  presentation  of  the  facts.  My  reasons  for  doing  so 
are  several. 

One  of  them  is  that  we  are  here  primarily  concerned  with 
psychological  phenomena  as  phenomena  of  Evolution ;  and, 
under  their  objective  aspect,  these,  reduced  to  their  lowest 
terms,  are  incidents  in  the  continuous  re-distribution  of 
Matter  and  Motion.  Hence  the  first  question  respecting 
the  nervous  system  as  studied  from  our  point  of  view  is — 
what  are  the  leading  facts  it  presents  as  expressed  in  terms 
of  Matter  and  Motion? 

Another  reason  is  that,  apart  from  any  doctrine  of  Evolu- 
tion, true  conclusions  respecting  psychical  phenomena  must 
be  based  on  the  facts  exhibited  throughout  organic  nature; 
and  that  the  above  statement  does  literally  nothing  else 
than  express  these  facts — expresses,  too,  all  that  direct 
induction  can  tell  us  respecting  their  essential  relations. 


14  THE  DATA  OF  PSYCHOLOGY. 

The  actions  of  all  organic  beings,  including  those  of  our 
own  species,  are  known  to  us  only  as  motions.  Shutting 
out  our  inferential  interpretations,  the  leaps  and  doublings 
of  the  escaping  prey  in  common  with  the  variously-adapted 
and  rapidly-changed  actions  of  the  pursuer,  are,  to  our  per- 
ceptions, nothing  but  movements  combined  in  particular 
ways;  and  so  too  are  the  changes  of  expression,  tones  of 
voice,  and  verbal  articulations  of  our  fellow-beings,  on  which 
we  put  such  hidden  implications.  As,  then,  science  requires 
us  to  distinguish  the  facts  as  actually  presented  from  the 
suppositions  we  ordinarily  join  with  them,  it  is  needful  to 
exhibit,  in  all  its  nakedness,  this  primordial  relation  between 
the  external  motions  and  their  internal  originator. 

Yet  a  further  reason  for  setting  out  thus,  is  that  we  so 
escape  from  pre-conceptions.  Those  who  bring  with  them 
to  the  investigation  of  psychical  phenomena,  the  hypotheses 
that  have  descended  to  us  from  the  past,  are  almost  sure  to 
be  more  or  less  biassed  thereby.  "While  intending  to  avoid 
assumptions  they  are  in  great  danger  of  having  their  con- 
clusions vitiated,  if  not  by  some  ancient  or  mediaeval  idea 
under  its  overt  form,  yet  by  corollaries  from  it  that  have 
unobtrusively  embodied  themselves  in  unsuspected  postu- 
lates. As  we  shall  presently  see,  even  physiologists  have 
been  in  some  cases  thus  misled. 

Hence,  then,  without  at  all  calling  in  question  the  truth 
of  those  other  and  quite  different  interpretations  of  nervous 
phenomena  that  are  tacitly  expressed  in  ordinary  language, 
it  is  proper  for  us  here  to  ignore  them.  Before  studying 
the  facts  from  a  psychological  point  of  view,  we  have  first  to 
study  them  from  a  physiological  point  of  view.  The  pri- 
mary truth  disclosed  by  the  facts  as  so  studied,  is  the 
universality  of  this  relation  between  the  degree  of  nervous 
evolution  and  the  quantity  and  heterogeneity  of  the  pro- 
duced motion.  We  now  pass  to  the  secondary  truths 
similarly  disclosed. 


CHAPTEE  n. 

THE  STEUCTimE  OF  THE  NERVOUS  SYSTEM. 

§  8.  An  outline  of  nervous  structure  must  precede  a 
detailed  account  of  it;  and  the  essential  facts  to  be  indi- 
cated in  an  outline  may  be  brought  most  clearly  into  view  by 
comparing  with  one  another  the  nervous  systems  possessed 
by  different  types,  and  by  different  grades  of  the  same  type. 
We  will  limit  our  comparisons  to  the  three  superior  sub- 
kingdoms  of  animals. 

A  minute  nodule  with  diverging  threads  constitutes  the 

rudimentary   nervous   system,    as   existing  in   the   lowest 

Mollusk.      In    the    Lamellibranchs    several    such    minute 

nodules,  or  ganglia,  are  distributed,  usually  in  pairs,  in 

different  parts  of  the  body;    and  beyond  the  free  fibres 

which  they  severally  give  off  to  neighbouring  organs,  there 

are  fibres  by  which  they  are  connected  together.     Gastero- 

pods,  considerably  higher  in  organization  and  activity,  have 

nervous  centres  among  which  a  considerable  heterogeneity 

is  produced  by  the  greater  size  of  some  than  of  others.    And 

besides  a  local  integration  of  paired  ganglia  into  single  bi- 

lobed  ganglia,  there  is  an  advance  in  general  integration, 

shown  by  a  clustering  of  the  more  important  ganglia  about 

the  head.    The  Cephalopods,  and  especially  the  dibranchiate 

division  of  them,  in  which  the  molluscous  type  reaches  its 

highest,  show  us,  carried  still  further,  that  integration  of 

the  nervous  system  due  to  simple  growth,  joined  with  that 

15 


Jg  THE  DATA  OP  PSYCHOLOGY. 

integration  due  to  concentration  and  coalescence  of  indepen- 
dent centres;  and  they  ako  show  us  the  differentiations 
involved  by  their  changes  of  size,  form,  and  distribution. 

A  delicate  cord  running  from  end  to  end  of  the  body,  and 
giving  off  lateral  fibres  in  pairs,  constitutes  the  nervous 
system  in  the  lower  Annulosa,  When  from  limbless 
Annelids  we  pass  to  the  Articulate  types,  composed  of  seg- 
ments bearing  limbs,  we  find  the  nervous  system  formed  of 
a  series  of  centres,  each  sending  fibres  to  the  different  organs 
of  its  own  segment,  and  all  of  them  united  by  a  thick 
cord  of  fibres  with  a  fused  cluster  of  similar  centres 
in  the  head.  In  the  la\:^ev  Articulata  there  is  an  increased 
relative  size  of  the  nervous  centres  as  compared  with  their 
connecting  structures;  an  actual  approach  of  the  chief 
nervous  centres  to  one  another,  both  longitudinally  and 
laterally;  and  a  final  coalescence  of  them.  This  integration 
disclosed  by  comparisons  of  lower  and  higher  types,  may 
also  be  observed  in  progress  during  the  development  of  the 
individual  insect  or  the  individual  crustacean.  And  along 
with  advancing  growth,  consolidation,  and  combination  of 
nervous  structures,  there  may  be  traced  an  increasing  un- 
likeness,  both  among  the  central  masses  themselves, 
among  their  connecting  cords,  and  among  their  divergent 
fibres. 

Such  traits  of  evolution  are  exhibited  under  another  form 
in  the  vertebrate  sub-kingdom.  Its  lowest  known  member, 
the  AmphioxitSy  has  a  simple  cranio-spinal  axis,  the  anterior 
extremity  of  which  is  not  made  appreciably  different  from 
the  rest  by  development  of  distinct  cerebral  ganglia,  and 
which  gives  off  lateral  nerves  that  have  but  minor  dis- 
similarities. The  cyclostome  Fishes,  possessed  of  cerebral 
ganglia  that  are  tolerably  manifest,  lead  us  to  the 
ordinary  fishes,  in  which  these  ganglia,  individually  much 
larger,  form  a  cluster  of  masses,  or  rudimentary  brain. 
Here,  however,  though  in  contact,  they  preserve  a 
serial  arrangement:    their  aggregation  is  little  more  than 


THE  STRUCTURE  OP  THE  NERVOUS  SYSTEM.        I7 

that  of  close  linear  succession.  But  in  the  highest  fishes 
certain  of  them  which  have  greatly  increased,  overlap  the 
others;  and  tend  so  to  form  a  more  compact,  as  well  as  a 
larger,  aggregate.  Superior  Reptiles  and  Birds  display  this 
relative  increase  of  certain  of  the  clustered  ganglia,  and  con- 
sequent obscuration  of  the  rest,  in  a  greater  degree.  It  is 
carried  still  further  in  the  inferior  Mammals.  From  them 
upwards,  the  leading  change  of  nervous  structure  is  an 
augmentation  of  the  two  largest  pairs  of  these  aggregated 
nervous  centres.  In  Man  one  pair  has  become  so  enormous 
that  the  others  are  most  of  them  hidden  by  it,  and  nearly 
merged  in  it.  Along  with  this  direct  inte- 

gration there  goes  on  the  indirect  integration  constituted 
by  more  intimate  and  multiplied  connections.  These 
are  both  longitudinal  and  transverse.  While  in  the 
Amphioxus,  the  cranio-spinal  axis  contains  but  a  small 
proportion  of  the  nerve-fibres  which,  running  longitudinally, 
serve  to  unite  its  different  parts;  in  a  superior  vertebrate 
animal,  such  uniting  nerve-fibres  are  among  the  chief  com- 
ponents of  the  cranio-spinal  axis.  And,  similarly,  while  the 
lateral  halves  of  the  cerebrum  are  but  slightly  connected  in 
Birds,  and  have  connections  that  are  relatively  deficient  in 
the  inferior  Mammals,  they  become,  in  the  highest  Mammals, 
joined  together  by  a  thick  mass  formed  of  innumerable 
fibres.  Meanwhile  there  have  been  arising  diffe- 

rentiations no  less  conspicuous.  Beyond  that  general  one 
due  to  development  of  the  anterior  end  of  the  cranio- 
spinal axis  into  cerebral  ganglia;  and  the  further  one 
of  like  nature  which  results  from  the  relatively-enor- 
mous growth  of  some  of  these;  other  differentiations 
have  been  constituted  by  the  local  unlikenesses  of  structure 
simultaneously  established.  As  they  enlarge,  the  greater 
ganglia  are  rendered  externally  dissimilar  from  the  rest  by 
the  formation  of  folds  or  convolutions;  and  their  internal 
parts  severally  acquire  distinctive  characters.  The  same 
thing  holds  of  the  peripheral  nervous  system.      Pairs  of 


^g  THE  DATA  OP  PSYCHOLOGY. 

nerves  that  were  originally  almost  uniform,  are  rendered 
multiform  by  the  much  greater  growth  of  some  than  of 
others,  and  by  the  inner  diiferences  that  accompany  these 
outer  differences. 

This  cursory  survey  of  the  nervous  system  under  the 
various  forms  it  presents  throughout  the  animal  kingdom, 
suffices  to  show  how  its  evolution  conforms  to  the  laws  of 
evolution  in  general.  We  are  also  shown  by  it  what  here 
more  immediately  concerns  us — that  while  the  rudimentary 
nervous  system,  consisting  of  a  few  threads  and  minute 
centres,  is  very  much  scattered,  its  increase  of  relative  size 
and  increase  of  complexity,  go  hand  in  hand  with  increased 
concentration  and  increased  multiplicity  and  variety  of  con- 
nections. Carrying  with  us  this  general  conception,  let  us 
now  study  its  structure  more  closely:  considering,  at  first, 
not  any  particular  forms  of  it  but  its  universal  form. 

§  9.  The  nervous  system  is  composed  of  two  tissues,  which 
both  differ  considerably  from  those  composing  the  rest  of  the 
organism.  They  are  usually  distinguished  from  one  another 
by  their  colours  as  grey  and  white,  and  by  their  minute  struc- 
tures as  vesicular  and  fibrous.  Chemical  analyses  have  not 
at  present  thrown  more  than  a  flickering  light  on  the  consti- 
tution of  nerve-matter  in  general,  or  on  the  constitution  of 
one  kind  of  nerve-matter  as  contrasted  with  the  other.  All 
that  can  be  asserted  with  safety  is,  that  each  kind  contains 
phosphatic  fats  and  protein-substances;  but  that  these  com- 
ponents are  both  differently  distributed  and  in  different 
states  in  the  two  tissues.  Let  us  see  what  we  are  told 
about  them  by  the  microscope,  aided  by  chemical  re-agents. 

Where  their  evolution  can  be  traced,  the  vesicles  or  cor- 
puscles of  the  grey  tissue  appear  to  take  their  rise  out  of  a 
nitrogenous  protoplasm,  full  of  granules  and  containing 
nuclei.  Round  these  nuclei  the  protoplasm  aggregates  into 
spheroidal  masses,  which,  becoming  severally  inclosed  in 
delicate  membranes  (in  many  cases  inferred  rather  than  seen) 


THE  STRUCTURE  OF  THE  NERVOUS  SYSTEM.         19 

are  so  made  into  nerve-cells.  The  protein-substance,  thus 
forming  alike  the  chief  contents  of  the  nerve-cells  and  the 
chief  part  of  their  matrix,  is,  though  coagulated,  soft.  The 
granules  imbedded  in  it,  both  within  and  without  the  cells, 
consist  of  fatty  matter.  And  on  comparing  together  nerve- 
cells  in  difPerent  stages,  there  are  seen  differences  in  the 
colours  of  the  granules,  indicating  a  progressive  meta- 
morphosis. To  complete  a  general  idea  of  the  grey  tissue, 
it  must  be  added  that  the  more  developed  of  these  nucle- 
ated cells,  or  nerve-corpuscles,  give  off  processes,  usually 
branched,  that  vary  in  number  and  degree  of  ramification; 
that  among  the  corpuscles  and  their  branches  are  dis- 
tributed the  terminations  of  nerve-fibres;  and  that  while  in 
some  nervous  centres  it  is  common  for  these  fibres  to  run 
directly  into  the  cells  or  to  be  continuous  with  certain  of 
the  processes,  in  other  nervous  centres  the  connections 
between  fibres  and  cells  are  rarely  if  ever  direct,  but  where 
they  exist,  are  made  through  the  remote  sub-divisions  of 
branches  given  off  by  both. 

When  we  pass  to  the  white  or  fibrous  tissue,  we  meet  with 
matters  that  at  first  sight  appear  as  distinct  from  the  othera 
in  nature  as  in  mode  of  arrangement.  The  fibres  prove  to 
be  minute  tubes.  Within  the  extremely  delicate  membrane 
of  which  each  tube  is  formed,  there  is  a  medullary  substance 
or  pulp,  which  is  viscid  like  oil,  has  a  pearly  lustre,  and 
consists  of  albuminous  and  fatty  substances.  But  unlike  sa 
the  contents  of  the  nerve-tubes  and  the  nerve-cells  thus 
appear  to  be,  a  careful  scrutiny  discloses  between  them  an 
essential  kinship.  For  imbedded  in  the  pulp  which  fills  the 
tube  or  sheath,  there  lies  a  delicate  fibre,  or  "axis-cylinder," 
which  is  composed  of  a  protein-substance.  Though 
chemically  similar  to  the  protein-substance  contained  in  the 
cells  of  the  vesicles,  this  is  physically  different ;  since,  besides 
being  comparatively  firm  or  solid,  it  is  uniform  and  con- 
tinuous, instead  of  having  its  continuity  broken  by  fat 
granules.    That  this  central  thread  of  protein-substance  is 


20  THE  DATA  OF  PSYCHOLOaY. 

the  essential  nerve,  to  which  the  sheath  of  medullary  matter 
with  its  surrounding  membranous  sheath  are  but  acces- 
sories, there  are  several  proofs.  One  is  that  in  the  lower 
animals,  as  well  as  in  the  embryos  of  the  higher,  no  me- 
dullary sheaths  exist:  the  nerve  consists  of  the  axis-cylinder 
and  its  protecting  membrane,  without  any  pulp  lying 
between  them-  Another  proof  is  that  at  the  peripheral  ter- 
minations of  nerves,  even  in  superior  animals,  the  medullary 
sheath  commonly,  if  not  always,  stops  short;  while  the  cen- 
tral thread,  covered  by  the  outermost  membrane,  continues 
further,  and  ends  in  delicate  ramifications  not  inclosed  in 
distinguishable  sheaths.  And  a  further  proof  is  that  where 
a  nerve-fibre  unites  with  a  nerve-cell,  the  medullary  sheath 
ceases  before  arriving  at  the  place  of  union;  while  the  axis- 
cylinder  joins  the  contents  of  the  cell,  and  its  protecting 
membrane  becomes  continuous  with  the  cell-wall,  where  this 
exists.  Hence  concluding,  as  we  are  warranted  in  doing, 
that  the  axis-cylinder  is  its  essential  part,  we  see  that 
the  matter  of  nerve-fibre  has  much  in  common  with  the 
matter  of  nerve-vesicle:  the  differences  between  them  ap- 
pearing to  be  mainly  that,  in  the  nerve-vesicle,  the  protein- 
substance  contains  more  water,  is  mingled  with  fat- 
granules,  and  forms  part  of  an  obviously  unstable  mass; 
whereas  in  the  nerve-tube  the  protein-substance  is  denser, 
and  is  distinctly  marked  off  from  the  fatty  compounds  that 
surround  it:  so  presenting  an  arrangement  that  is  relatively 
stable. 

What  is  the  meaning  of  this  difference?  Before  seeking 
an  answer  we  must  remember  that  compound  substances 
undergo  two  fundamentally  different  kinds  of  metamorpho- 
sis— one  in  which  the  components  are  some  or  all  of  them 
dissociated  and  distributed  through  surrounding  space, 
either  apart  or  in  new  combinations;  and  one  in  which  the 
components,  instead  of  being  dissociated,  are  merely  re-ar^ 
ranged,  so  as  to  alter  the  perceptible  properties  of  the 
mass  without  destroying  its  physical  continuity.     The  first 


THE    STRUCTURE  OF  THE  NERVOUS  SYSTEM.        21 

we  call  decomposition;  the  second  isomeric  transforma- 
tion. These  forms  of  change  are  further  distinguished 
in  this,  that  the  one  is  usually  accompanied  by  a  great 
dissipation  of  motion,  whereas  the  motion  given  out 
or  taken  up  along  with  the  other  is  relatively  insignificant. 
There  is  yet  a  third  contrast.  After  decomposition  the 
separated  components  cannot  be  readily  made  to  resume 
their  previous  relations:  often  it  is  impossible  to  combine 
them  again ;  and  in  most  other  cases  it  is  difficult  to  do  this. 
But  in  many  instances  of  isomeric  transformation,  resump- 
tion of  the  original  form  may  be  produced  by  a  very  mod- 
erate change  of  conditions. 

Now  the  two  kinds  of  molecular  change  thus  strongly 
contrasted,  are  the  two  kinds  of  molecular  change  which  we 
have  reason  to  suspect  are  undergone  by  the  two  forms  of 
nervous  matter.  While  the  protein-substance  mingled  with 
fat-granules  in  the  vesicles,  is  habitually  decomposed;  the 
protein-substance  forming  the  axes  of  the  nerve-fibres  is 
habitually  changed  from  one  of  its  isomeric  states  to  another. 
Such,  at  least,  is  the  assumption  here  made,  in  conformity 
with  the  conclusion  drawn  in  the  Principles  of  Biology 
(§  302) ;  where  it  was  argued  that  the  propagation  of  mole- 
cular disturbances  from  one  place  in  an  organism  to  another, 
tends  so  to  modify  the  mingled  colloidal  substances  as  to 
produce,  between  the  two  places,  a  form  of  colloid  that 
undergoes  isomeric  transformation  when  disturbed,  and  com- 
municates the  disturbance  in  undergoing  the  transformation; 
and  where  it  was  argued  that  this  easily-transformable 
colloid,  having  had  such  a  change  set  up  at  one  end  of  it 
and  passed  on  to  the  other,  giving  out  in  the  process  some 
molecular  motion  and  consequently  falling  in  temperature, 
immediately  re-absorbs  from  the  adjacent  tissues  permeated 
by  blood,  an  amount  of  molecular  motion  equal  to  that  which 
was  lost :  thereupon  resuming  its  previous  isomeric  state,  and 
its  fitness  for  again  propagating  a  wave  of  transformation. 

Much  as  there  is  here  of  hypothesis,  the  indirect  evidence 


22  THE  DATA  OP  PSYCHOLOGY. 

makes  it  probable  that  if  this  is  not  the  true  interpretation, 
the  true  interpretation  is  analogous  to  it.  That  the  matter 
contained  in  the  vesicles  is  the  seat  of  destructive  molecular 
changes,  with  accompanying  disengagement  of  motion, 
while  the  matter  contained  in  the  tubes  is  the  seat  of 
changes  which,  of  whatever  special  nature,  do  not  involve 
much  destructive  decomposition  and  disengagement  of 
motion,  are  beliefs  for  which  we  have  several  warrants; — 
among  others,  the  following.  The  grey  tissue 

contains  far  more  water  than  the  white  tissue:  the  propor- 
tion of  solids  to  water  being  about  12  per  cent,  in  the  grey 
tissue,  while  in  the  white  tissue  it  is  some  25  per  cent. 
Now  abundance  of  water  facilitates  molecular  change,  and 
habitually  characterizes  parts  in  which  the  rate  of  molecular 
change  is  high.  Hence  the  implication  is  that  the  grey 
matter  undergoes  metamorphosis  with  much  greater  rapidity 
than  the  white.  Stronger  evidence  is  afforded  by  the 

fact  that  the  grey  or  vesicular  substance  has  a  vascularity 
immensely  exceeding  that  of  the  white  or  fibrous  sub- 
stance. On  comparing  the  net-works  of  blood  vessels  that 
permeate  the  two,  the  difference  is  conspicuous;  and  it  is 
much  greater  than  at  first  appears.  An  estimate  based  on 
measurements,  proves  that  a  given  bulk  of  the  one  contains 
about  five  times  as  many  capillaries  as  an  equal  bulk  of  the 
other.*    Now  since  these  minute  canals  that  bring  and  take 

•  The  drawing  on  which  this  estimate  is  based,  is  contained  in  the 
Manual  of  Human  Histology,  by  A.  KSlliker :  translated  and  edited  by 
George  Busk,  F.  R.  S.,  and  Thomas  Huxley,  F.  R.  S.  The  estimate  is 
easily  m*<le.  A  number  of  equi-distant  parallel  lines  being  drawn  trans- 
versely through  the  two  net-works,  the  number  of  places  at  which  one  of 
these  lines  crosses  blood-vessels  within  a  given  length  (say  an  inch)  ia 
counted,  and  the  like  being  done  with  an  equal  length  of  each  of  the 
other  parallel  lines  traversing  the  same  net-work,  there  is  obtained,  by 
taking  an  average,  the  number  of  vessels  usually  met  with  in  a  specified 
distance.  The  like  process  is  then  gone  through  with  lines  of  the  same 
length  traversing  the  other  net-work.  These  averages  do  not,  however, 
truly  express  the  comparative  numbers  of  such  intersections  in  the  two 
net-works ;  since  the  meshes  of  the  one  are  unlike  those  of  the  other  in 


THE  STRUCTURE  OF  THE  NERVOUS  SYSTEM.    23 

away  materials,  must  be  numerous  in  proportion  as  com- 
position and  decomposition  are  quick;  we  may  infer  a  great 
difference  between  the  rates  of  destructive  change  in  the 
two  tissues.  Another  contrast  supports  this  con- 

clusion no  less  strongly.  The  unstable  granular  protoplasm 
contained  in  the  corpuscles,  is  shielded  from  adjacent  dis- 
turbing forces  by  a  membrane  which,  even  where  thickest, 
is  so  delicate  that  its  existence  can  be  demonstrated 
only  by  the  help  of  re-agents;  and  which  in  many 
corpuscles  cannot  be  made  visible  at  all.  Hence  between 
the  matter  contained  in  these  corpuscles,  or  vesicles, 
and  the  streams  of  blood  that  run  among  them  so 
abundantly,  are  interposed  little  else  than  the  delicate  walls 
of  the  capillary  blood-vessels;  and  thus  the  disturbing 
substances  brought  by  each  capillary,  can  pass  with  the 
least  possible  hindrance  into  the  unstably-arranged  contents 
of  the  neighbouring  vesicles.  Quite  otherwise  is  it  with 
the  relations  of  the  blood  to  the  contents  of  nerve-tubes. 
The  wall  of  each  nerve-tube  is  thick  enough  to  make  it 
easily  demonstrated ;  and  between  it  and  the  central  thread 
of  essential  matter,  comes  the  coat  of  nerve-medulla. 
Through  these  barriers  the  disturbing  agents,  carried  among 
the  nerve-tubes  by  sparingly-distributed  capillaries,  cannot 
readily  pass;  and  the  essential  nerve-thread  is  prevented  from 
having  molecular  changes  set  up  in  it  at  places  between 
its  two  extremes.  This  protection  suffices  so  long  as  the 
disturbing  agents  remain  normal  in  their  amounts ;  but  when 
they  become  excessive,  as  they  do  if  the  blood-vessels  become 
congested,  local  changes  in  the  nerve-threads  are  caused: 
whence  one  kind  of  neuralgia.    It  should  be  added  that  by 

shape.  Hence  it  is  needful  to  draw  an  equal  number  of  parallel  longitu- 
dinal lines  ;  and  to  repeat  with  them  this  process  of  averaging.  By  tak- 
ing the  means  between  the  resulting  numbers  and  the  previous  numbers, 
we  get  a  correct  representation  of  the  relative  frequencies  with  which 
the  vessels  occur  in  space  of  one  dimension.  To  ascertain  their  relative 
frequencies  in  space  of  three  dimensions,  or  in  solid  tissue,  it  is  of  course 
needful  simply  to  cube  the  two  numbers  so  arrived  at. 


24  THE  DATA  OF  PSYCHOLOGY. 

this  sheathing  of  nerve-medulla,  the  essential  nerve-threads, 
besides  being  shielded  against  disturbances  from  neighbour- 
ing currents  of  blood,  are  shielded  against  disturbances  from 
nerve-threads  in  the  same  bundle.  Were  "  axis-cylinders  " 
lying  in  lateral  contact  not  thus  coated,  a  molecular  change 
propagated  through  one  would  set  up  molecular  changes  in 
its  neighbours;  as,  in  fact,  it  does  in  an  early  stage  of 
ataxy,  characterized  by  loss  of  the  medullary  sheaths. 
Hence,  too,  the  explanation  of  that  normal  absence  of  me- 
dullary sheaths  which  sundry  nervous  structures  show  us. 
For  among  the  Invertebrata,  in  which  this  normal  absence 
occurs,  the  fibres  contained  in  the  same  bundle  have 
nothing  like  those  many  and  varied  distinctions  which  they 
have  in  the  higher  animals:  they  have  termini  of  which 
the  structures  and  functions  are  much  less  differentiated. 
Similarly  with  those  bundles  of  grey  or  non-medullated 
fibres,  contained  in  the  sympathetic  system  of  vertebrate 
animals;  for  these  bundles,  serving  to  establish  relations 
among  the  viscera,  each  of  which  is  much  less  divided  into 
parts  that  act  independently,  there  needs  no  such  perfect  in- 
sulation of  the  nerve-fibres.  And  the  like  holds  even  in  cer- 
tain portions  of  the  peripheral  cerebro-spinal  system ;  as  the 
olfactory  expansion,  which  consists  of  an  extensive  plexus 
of  non-medullated  fibres,  and  which  has  the  peculiarity 
that  different  parts  of  its  area  are  not  acted  upon  sepa- 
rately. 

The  evidences,  direct  and  indirect,  thus  justify  us  in 
concluding  that  the  nervous  system  consists  of  one  kind 
of  matter  under  different  forms  and  conditions.  In  the 
grey  tissue  this  matter  exists  in  masses  containing  cor- 
puscles, which  are  soft  and  have  granules  dispersed  through 
them,  and  which,  besides  being  thus  unstably  composed, 
are  placed  so  as  to  be  liable  to  disturbance  in  the  greatest 
possible  degree.  In  the  white  tissue  this  matter  is  collected 
together  in  extremely  slender  threads,  that  are  denser,  that 
are  uniform  in  texture,  and  that  are  shielded  in  an  unusual 


THE  STRUCTURE  OP  THE  NERVOUS  SYSTEM.        25 

manner  from  disturbing  forces,  except  at  their  two  extre- 
mities. And  the  implication  on  which  we  henceforth  pro- 
ceed is,  that  the  masses,  unstably  constituted  and  con- 
ditioned, are  seats  of  destructive  molecular  changes,  and 
disengagement  of  motion ;  while  the  stably  constituted  and 
conditioned  threads,  are  the  seats  of  molecular  changes  that 
are  not  destructive,  and  are  probably  isomeric. 

§  10.  Nerve-tubes  with  their  contained  protein-threads, 
and  nerve-cells  with  their  contained  and  surrounding 
masses  of  changing  protein-substance,  are  the  histologic 
elements  of  which  the  nervous  system  is  built  up; 
and  we  have  now  to  ask  in  what  way  they  are  put 
together.  We  will  begin  with  the  peripheral  termina- 
tions of  the  nerve-tubes;  or  rather,  with  those  of  them 
which  lie  on  the  outer  surface. 

Suppose  the  skin,  including  those  introverted  portions 
of  it  which  form  the  receptive  areas  of  the  special 
senses,  to  be  marked  all  over  in  such  a  way  as  to  form  a 
net-work.  Suppose  the  meshes  of  this  net-work  to  vary 
extremely  in  their  sizes;  so  that  while  in  some  places  they 
are  as  large  as  those  of  a  fishing-net,  they  are  in  other  places 
not  large  enough  to  admit  the  point  of  a  needle.  Or,  to 
speak  specifically,  suppose  that  on  the  middle  of  the  back 
the  meshes  are  some  2^  inches  in  diameter,  and  that  being 
equally  large  over  the  middles  of  the  fore-arms,  and  the 
middles  of  the  thighs,  they  diminish  to  2  inches  and  less 
over  the  neck  and  breast,  to  1^  inches  at  the  extremities 
of  the  legs,  to  1:|  inches  on  the  backs  of  the  hands,  to  less 
than  an  inch  on  the  forehead,  to  less  than  half-an-inch  over 
the  cheeks  and  over  the  palms  of  the  hands,  to  a  quarter 
of  an  inch  and  less  over  the  fingers,  to  a  twelfth  of  an  inch 
at  the  inner  tips  of  the  fingers,  and  at  the  tip  of  the  tongue 
to  one  twenty-fourth  of  an  inch  in  diameter;  and  sup- 
pose, further,  that  over  the  back  of  that  dermal  sac  which 
forms  the  eye,  these  meshes  are  so  small  that  a  microscope 


26  THE  DATA  OF  PSYCHOLOGY. 

is  required  to  distinguish  them.  Having  imagined  such  a 
net-work  of  which  the  meshes,  irregularly  polygonal  in 
their  outlines,  are  thus  wide  over  parts  of  the  surface  that 
have  but  little  variety  of  converse  with  the  external  world, 
and  become  smaller  in  proportion  as  the  surfaces  have 
multiplied  and  variable  contacts  with  things;  we  shall  have 
gained  an  approximate  idea  of  the  relations  among  the 
separate  local  areas  in  which  there  arise  independent  nerves. 
To  complete  the  conception,  however,  something  else  must 
be  supposed.  The  large  meshes  we  must  represent  as 
marked  out  by  very  broad  lines — say  a  quarter  of  an  inch 
broad  where  the  meshes  are  largest.  We  must  imagine 
them  narrowing  as  the  meshes  become  smaller;  until, 
when  we  come  to  the  meshes  over  the  surface  of  the 
retina,  the  dividing  lines  have  dwindled  to  the  thick- 
ness of  a  gossamer  thread.  And  now  let  us  conceive  that 
within  each  of  these  areas,  large  or  small  as  it  may  happen, 
there  exists  a  plexus  of  fibres,  formed  of  the  essential  nerve 
substance,  that  are  continuous  with  one  another,  but  have 
no  connection  with  the  fibres  occupying  adjacent  areas. 
Not,  indeed,  that  we  must  conceive  any  sharp  limitation  of 
the  space  occupied  by  each  plexus.  We  must  assume  that 
the  line  separating  two  areas,  here  very  broad  and  here  very 
narrow,  covers  a  space  into  which  fibres  from  both  the  areas 
run,  without  joining  one  another.  Hence  the  area  belong- 
ing to  each  independent  plexus,  is  the  internal  area  of  the 
mesh,  plus  the  space  occupied  by  its  circumscribing  broad 
or  narrow  line;  and  the  breadth  of  the  line  represents  the 
extent  to  which  adjacent  areas  overlap.  Such, 

then,  are  the  peripheral  expansions  of  those  nerves  which 
are  liable  to  be  acted  on  by  external  forces.  Here  each 
monopolizes  a  relatively-great  tract  of  the  surface,  and  here 
an  extremely  minute  one.  Each  is  an  independent  agent — 
each  is  capable  of  having  a  change  set  up  in  it  without 
changes  being  set  up  in  its  neighbours.  The  skin  is,  as  it 
were,  occupied  all  over  with  separate  feelers,  that  are  here 


THE  STRUCTURE  OP  THE  NERVOUS  SYSTEM.        27 

widely  scattered,  here  clustered,  and  here  crowded  together 
as  closely  as  maintenance  of  their  individualities  will  allow. 
From  the  nerve-plexus  occupying  one  of  these  areas,  there 
takes  its  rise  the  central  fibre,  or  axis-cylinder,  of  a  nerve- 
tube.  Coated  with  its  medulla  and  inclosing  sheath,  it 
takes  its  way  from  the  surface  inwards,  and,  proceeding 
without  any  branch  or  junction,  eventually  reaches  a  mass 
of  grey  matter  with  imbedded  vesicles — a  nerve-centre  or 
ganglion.  Into  the  substance  of  this  the  essential  nerve- 
thread  runs,  becoming  divested  of  its  medullary  sheath; 
and  where  the  structure  is  least  involved,  the  essential 
nerve-fibre  frequently  if  not  always  ends  in  a  nerve-vesicle. 
In  such  simple,  and  what  we  may  call  typical,  centres,  there 
branches  out  from  some  other  part  of  the  nerve-vesicle, 
another  nerve-fibre  which,  similarly  inclosed  in  its  double 
sheath,  pursues  an  outward  course,  ordinarily  along  the 
same  general  route  as  the  first,  until,  reaching  the  same 
part  of  the  body,  it  buries  itself  in  a  bundle  of  muscular 
fibres  amid  which  its  ramifications  end.  Thus  we  have  as 
the  elements  of  what  is  called  a  nervous  arc — 1,  a  peri- 
pheral expansion,  placed  where  it  is  liable  to  be  disturbed 
by  an  external  agent,  and  so  formed  as  to  be  most  easily 
disturbed;  2,  a  connected  fibre  capable  of  being  readily 
affected  by  disturbances  at  this  outer  end,  but  shielded  from 
disturbances  elsewhere;  3,  at,  or  near,  the  inner  end  of  this 
fibre,  a  corpuscle  of  unstably-arranged  substance,  apt  to 
give  out  much  molecular  motion  when  disturbed;  4,  a 
second  fibre  diverging  from  the  corpuscle,  or  its  neigh- 
bourhood, and  subject  to  disturbance  from  the  molecular 
motion  disengaged  near  its  origin,  but  protected  from  other 
influences;  5,  at  the  remote  extremity  of  this  second  fibre, 
a  subdivided  termination  amid  a  substance  that  contracts 
greatly  when  disturbed,  and  which,  in  contracting,  moves 
the  part  of  the  body  in  which  the  first  fibre  took  its  rise. 
Fig.  1  is  a  diagram  representing  these  elements  of  a  nervous 
arc:  A  being  the  first,  or,  as  it  is  called,  afferent  nerve, 


28  THE  DATA  OP  PSYCHOLOGY. 

with  its  peripheral  expansion  a;  B  being  the  nerve-cor- 
puscle or  ganglion-cell;  and  C  the  second,  or  efferent, 
nerve,  with  its  termination  c. 


Fig.S. 


tf^re^eeU. 


This  arrangement  of  parts  is  perpetually  repeated  through- 
out the  nervous  system;  and  if  we  generalize  the  concep- 
tion somewhat  by  supposing  that  the  commencement  a  is 
not  necessarily  external,  but  may  be  on  an  inner  surface,  or 
within  an  organ,  while  the  termination  c  is  not  necessarily 
in  a  muscle  but  may  be  in  a  gland ;  we  shall  have  a  concep- 
tion that  is,  in  a  certain  sense,  universally  applicable.  I 
say  in  a  certain  sense,  because,  until  another  element  is 
added,  the  conception  is  incomplete.  These  coupled  nerves, 
with  the  ganglion-cell  acting  as  a  direct  or  indirect  link 
between  them,  recurring  everywhere  in  substantially  the 
same  relations,  appear  to  form  a  compound  structure  out 
of  which  the  nervous  system  is  built — its  unit  of  composi- 
tion; But  this  is  not  so.  By  multiplication  of  such  arcs 
we  may  get  a  multitude  of  separate  nervous  agencies, 
but  not  a  nervous  system.  To  produce  a  nervous  system 
there  needs  an  element  connecting  each  such  nervous  arc 
with  the  rest — there  needs  a  third  fibre  running  from  the 
ganglion-cell,  or  its  neighbourhood,  to  some  place  where 
other  communicating  fibres  come;  and  where,  by  direct  or 
indirect  junctions,  actual  or  approximate,  the  primary 
couples  of  nerves  may  be  brought  into  relation.  That  is, 
there  requires  what  we  may  call  a  centripetal  nerve.*    In 

*  The  words  centripetal  and  centrifugal  are  occasionally  used  in  nerve- 
physiology  as  the  equivalents  of  afferent  and  efferent.  But  as  afferent  and 
efferent  are  by  far  the  most  generally  adopted,  and  are  also  the  most  descrip- 
tive, it  seems  to  me  that  the  word  centripetal  may  with  advantage  have  this 
more  special  meaning  given  to  it ;  and  centrifugal  the  correlative  meaning 


THE  STRUCTURE  OF  THE  NERVOUS  SYSTEM.        29 

Fig.  2  is  shown,  diagrammatically,  the  relation  in  which 
this  stands  to  the  others.  A  centripetal  nerve  being  added, 
there  results  what  we  may  fairly  regard  as  the  unit  of  com- 
position of  the  nervous  system.  We  shall  have  presently 
to  recognize  certain  fibres  which  this  conception  does  not 
include.  But  they  are  not  essential;  for  a  nervous  system 
is  possible  without  them.  Let  us,  then,  taking  this  as  our 
unit  of  composition,  consider  the  general  method  after  which 
a  nervous  system  is  constructed. 

§  11.  The  fibres  represented  in  the  above  diagrams,  do 
not  ordinarily  pursue  their  respective  courses  by  themselves: 
they  proceed  in  company,  as  shown  in  Fig.  3.  The  afferent 
nerves  arising  at  a,  in  separate  but  adjacent  areas  on  the 
skin,  or  in  other  organs  recipient  of  external  impressions, 
converge;  and,  while  maintaining  their  separate  indivi- 
dualities, become  united  into  a  bundle  inclosed  in  a  sheath. 

"  \j      V  Fig.  8.  ^ 


Other  sheathed  bundles  of  fibres  from  other  clustered  areas 
in  the  same  region,  presently  join  them,  and  run  along  with 
them  in  a  compound  bundle,  until  they  eventually  reach  the 
mass  of  imbedded  nerve-vesicles  constituting  a  ganglion  or 
nervous  centre  B.  Similarly  the  efferent  nerves  which  have 
their  roots  in  this  ganglion,  issue  from  it  as  a  bundle,  which, 
commonly  inclosed  in  the  same  general  sheath  as  the  afferent 
nerves,  goes  back  to  the  part  of  the  body  whence  these 
arose;  and  secondary  bundles  of  these  efferent  nerves, 
diverging  and  re-diverging  from  one  another  as  they  enter 
this  part,  as  at  c,  finally  become  lost  in  its  various  muscles. 


30  THE  DATA  OF  PSYCHOLOGY. 

In  like  manner  tlie  centripetal  fibres  d,  originating  in  this 
ganglion,  take  their  common  course,  joined  perhaps  by  other 
fibres  originating  elsewhere,  towards  a  ganglion  E,  that  is 
larger  and  has  more  numerous  connections.  Of  course  the 
clustered  lines  and  spotted  circles  in  Fig.  3,  are  entirely 
diagrammatic — give  no  idea  of  the  separate  nerves  and 
bundles  and  ganglia  as  they  actually  exist;  but  merely  of  the 
relations  in  which  they  stand  to  one  another.  It  should  be 
added  that  the  more  central  ganglion,  to  which  converge 
other  bundles  of  centripetal  nerves  (together  with  some 
afferent  nerves  that  pass  through  inferior  ganglia  without 
stopping)  may  itself  be  subordinate  to  a  still  superior,  or 
still  more  central,  ganglion.  To  this  it  gives  off  what  may 
be  called  superior  centripetal  nerves;  and  other  nerves  of 
the  same  or  of  a  lower  order  being  brought  to  it,  this  highest 
ganglion  becomes  a  place  where  there  are  established 
communications  among  all  the  subordinate  and  sub-subordi- 
nate ganglia,  with  their  afferent  and  efferent  fibres. 

One  further  kind  of  connection  exists.  The  immense 
majority  of  animals,  have  their  parts  symmetrically  arranged 
— sometimes  radially  but  more  frequently  bi-laterally.  For 
the  corresponding  parts  there  are  habitually  corresponding 
ganglia;  and  the  connections  that  remain  to  be  named  are 
those  between  these  corresponding  ganglia,  or  ganglia  which 
belong  to  the  same  grade.  Such  connections  consist  of 
what  are  called  commissural  fibres.  They  are  indicated  at  &, 
where  they  transversely  join  the  structure  shown  in  detail, 
with  the  answering  structure  belonging  to  the  other  side  of 
the  body.  The  word  commissural  is,  indeed,  sometimes 
used  in  a  wider  sense:  including  fibres  that  unite  ganglia  of 
different  grades.  But  since  the  great  majority  of  the  fibres 
called  commissural  are  those  which  join  duplicate  ganglia,  or 
else  ganglia  that  occupy  like  relations  in  the  hierarchy,  it 
will,  I  think,  conduce  to  clearness  to  restrict  its  application 
to  these:  leaving  the  word  centripetal  for  fibres  which  con- 
nect ganglia  of  lower  orders  with  those  of  higher  orders. 


THE  STRUCTURE  OF  THE  NERVOUS  SYSTEM.    31 

The  commissures  thus  bringing  into  relation  the  members  of 
each  pair  of  centres,  inferior  or  superior,  and  so  linking  the 
two  halves  of  the  nervous  system,  complete  the  nervous 
communications  throughout  the  organism. 

This  description,  purposely  generalized  with  a  view  of 
exhibiting  the  principles  of  nervous  organization,  apart 
from  any  particular  type,  may  be  fitly  supplemented  by  the 
description  of  a  special  structure  that  illustrates  them. 
Each  sucker  on  any  arm  of  a  cuttle-fish,  has  a  ganglion 
seated  beneath  it.  To  this  descend  the  afferent  nerves  that 
are  affected  by  touching  the  sucker;  and  from  it  ascend  the 
efferent  nerves  distributed  to  the  muscular  fibres  of  the 
sucker.  These  form  a  local  nervous  system  that  is  ex- 
perimentally proved  to  have  a  certain  completeness  in  itself. 
But  now  from  the  ganglion  underneath  each  sucker,  fibres 
run  along  the  arm,  in  company  with  fibres  from  all  similar 
ganglia  in  the  arm;  and  this  bundle  of  centripetal  fibres 
eventually  reaches  a  ganglion  at  the  base  of  the  arm.  Each 
arm,  similarly  constructed,  thus  has  a  chief  nervous  centre 
in  which  the  fibres  from  all  its  minor  nervous  centres  are 
brought  into  communication.  Further,  all  round  the  ring 
formed  by  the  united  base  of  the  arms,  there  runs  an  an- 
nular commissure  connecting  these  superior  ganglia.  And 
then  from  each  of  them  is  given  off  a  bundle  of  fibres  that 
proceed  centripetally  to  a  still  higher  centre — the  cephalic 
ganglion ;  where,  consequently,  nerves  from  all  the  arms  are 
brought  into  direct  communication  with  one  another,  and 
also  into  communication  with  nerves  arriving  from  ganglia 
in  other  parts  of  the  body.  Omitting  details  and  qualifica- 
tions, not  essential  to  such  a  conception  as  concerns  us  here, 
we  thus  see  that  in  nervous  structure  there  is  a  centraliza- 
tion and  re-centralization,  that  is  carried  far  in  proportion 
as  the  organization  is  high. 

§  12.  We  may  be  sure  that  along  with  a  principle  of  ar- 
rangement among  connecting  structures,  there  goes  some 


32  THE  DATA  OF  PSYCHOLOGY. 

principle  of  composition  in  the  centres  that  are  connected; 
which  are  not  simply  places  for  the  meeting  of  fibres,  but 
places  in  which  there  exist  agents  liable  to  be  acted  on  by 
the  in-coming  fibres  and  capable  of  acting  on  the  out-going 
fibres.  Respecting  the  principle  of  composition,  our  reason- 
ings must  be  mainly  hypothetical;  but  they  will,  I  think, 
prove  of  some  worth,  by  leading  us  to  conclusions  that  har- 
monize with  observation,  so  far  as  this  carries  us. 

In  ascending  from  the  lowest  to  the  highest  types  of  the 
nervous  system,  we  see  that  the  distribution  and  combi- 
nation of  nerve-fibres  are  so  modified,  as  to  make  possible  an 
increasing  multiplicity,  variety,  and  complexity  of  relations 
among  different  parts  of  the  organism.  What  kind  of  mo- 
dification does  this  necessitate  at  places  where  the  nerve- 
fibres  are  put  in  communication?  Without  assuming  that 
two  fibres  which  bring  two  parts  of  the  organism  into  rela- 
tion, are  always  united  at  their  central  extremities  by  an 
intermediate  nerve-corpuscle,  it  may  be  safely  assumed  that 
continuity  between  their  central  extremities  must  be  effected 
either  by  a  nerve-corpuscle  or  by  some  less-defined  portion 
of  grey  substance;  and  it  is  clear  that  in  proportion  to  the 
number  of  different  connections  to  be  established  among  the 
nerves  coming  to  any  ganglion,  must  be  the  number  of  the 
more  or  less  independent  portions  of  grey  substance  re- 
quired to  establish  them.  Let  us  consider  the  implications. 
Suppose  that  a  and  &,  Fig.  4,  are  two  points  in  the  or- 
ganism. To  join  the  nerves  proceeding  from  them,  there 
needs  only  the  single  ganglion-cell  A.  Similarly,  to  bring 
into  nervous  relation  the  points  c  and  d,  the  single  ganglion- 
cell  B  suffices.  So  long  as  A  and  B  remain  unconnected, 
these  two  simple  relations  are  the  only  possible  ones  among 
the  points  a,  &,  c,  d.  But  now  assume  that  from  A  and  B 
there  run  fibres  to  the  centre  C — not  a  single  fibre  from 
each,  but  two  fibres,  one  of  which  in  each  case  proceeds  from 
a  or  6,  and  from  c  or  d.  This  being  so,  there  may  be  formed 
at  C,  eleven  simple  and  compound  relations:    these  four 


THE  STRUCTURE  OF  THE  NERVOUS  SYSTEM.        33 

points  can  be  arranged  into  six  groups  of  two,  a  &,  a  c,  a  d^ 
b  c^h  djC  d;  into  four  groups  of  three,  h  a  c^h  a  d,  a  c  d,  ch  d; 
and  into  one  group  of  four,  abed.  Hence,  supposing  the 
centre  C  to  be  made  up  of  the  independent  cells,  or  portions 
of  grey  substance,  severally  serving  to  link  the  members  of 
a  group  into  a  separate  combination,  there  must  be  at 
least  eleven  such.  If,  again,  from  this  centre  C,  we  assume 
that  there  run  adequately  numerous  fibres  to  the  higher 
centre  F,  and  that  this  is  also  duly  connected  through 
the  centres  D  and  E,  with  the  points  e,  f,  g,  h;  then 
the  possible  number  of  groups,  simple  and  compound, 
that  may  be  formed  at  F,  will  amount  to  247;  and  to 
unite  the  members  of  each  group  so  that  it  may  be  inde- 
pendent of  the  rest,  there  must  be  at  least  247  connect- 

FIg.4. 


ing  links  at  the  centre  F.  "Without  pursuing  the  calcu- 
lation, it  will  be  manifest  that  as  these  points  in  the  or- 
ganism increase  in  number,  and  as  the  clusters  of  them 
that  are  to  be  brought  into  relation  become  larger  and  more 
various,  the  central  elements  through  which  their  relations 
are  established  must  grow  multitudinous.  An  in- 

adequate conception,  however,  is  thus  reached ;  for  we  have 
considered  only  the  requisites  for  forming  among  these 
points,  the  greatest  nwrriher  of  different  groups,  simple  and 
compound;   ignoring  the   different  orders  in  which   the 


34  THE  DATA  OF  PSYCHOLOGY. 

members  of  each  group  may  be  combined.  Two  things  can 
be  arranged  in  succession  in  only  2  different  ways;  three 
things  can  be  arranged  in  6  different  ways;  four  things  in 
24  ways;  five  things  in  120  ways;  six  things  in  720  ways; 
seven  things  in  5,040  ways;  and  so  on  in  a  progression 
increasing  with  enormous  rapidity.  Assuming,  then,  that 
at  the  centre  F,  certain  points,  a,  b,  c,  d,  e,  are  to  be  com- 
bined, not  in  this  succession  only,  but  in  all  possible  suc- 
cessions, there  will  require  120  different  links  of  connec- 
tion for  this  one  group  of  five  points  only.  These  links, 
whether  separate  vesicles  or  less-differentiated  portions  of 
grey  matter,  must  occupy  a  considerable  space;  and  sup- 
posing they  are  aggregated  near  those  pre-existing  cells 
or  links  which  they  have  to  re-combine  in  various  orders, 
there  may  result  a  protuberance  from  the  centre  F,  as  shown 
at  G.  If  we  suppose  that  instead  of  a  group  of  five,  a  group 
of  six  is  to  have  its  members  thus  variously  combined; 
or  if  instead  of  one  group  to  be  so  dealt  with,  there  are 
many;  this  lateral  outgrowth  may  become  relatively  very 
large.  And  since  its  vesicles,  or  portions  of  grey  matter, 
will  be  much  more  bulky  than  the  fibres  running  from  them 
to  the  members  of  groups  which  they  combine,  there  may 
be  expected  to  arise,  as  at  H,  a  lateral  centre  attached  to 
the  original  centre,  F,  by  a  pedicle  of  fibres. 

Of  course  these  diagrams  and  numbers  are  intended  to 
convey  nothing  but  a  general  idea  of  the  principle  of  com- 
position of  nerve  centres — not  to  represent  any  actual  com- 
position. It  would  be  an  absurd  assumption  that  among  a 
number  of  points  in  the  body,  there  have  to  be  formed  as 
many  unlike  groups  as  are  theoretically  possible;  and  it  is 
not  to  be  supposed  that  the  members  of  any  group  need 
ever  to  be  combined  in  as  many  different  orders  as  they 
might  be  combined.  But  while,  on  the  one  hand,  the  above 
description  greatly  over-states  the  accumulation  of  nerve- 
vesicles,  or  their  equivalents,  implied  by  such  correlations  as 
are  actually  required  among  a  given  number  of  points  in  the 


THE  STRUCTURE  OF  THE  NERVOUS  SYSTEM.        35 

organism;  it  immensely  under-states  the  number  of  points 
to  be  so  correlated,  as  well  as  the  number,  and  variety,  and 
complexity,  of  the  groups  into  which  they  are  to  be  com- 
bined. The  places  from  which  afferent  nerves  proceed,  as 
well  as  the  places  to  which  efferent  nerves  proceed,  are 
multitudinous.  Very  large  groups  of  such  places  have  their 
members  put  in  simultaneous  communication.  The  different 
groups  so  formed  are  innumerable.  And  extremely  varied 
relations  of  succession  are  established  among  members  of 
the  same  group ;  as  well  as  among  different  groups.  Hence 
we  are  safe  in  asserting  that  along  with  an  increasing  multi- 
plicity and  heterogeneity  of  nervous  connections,  there  must 
go  increasing  massiveness  of  the  nervous  centres,  or  accu- 
mulations of  vesicular  matter. 

One  further  corollary  deserves  noting.  Each  vesicle,  or 
each  portion  of  grey  matter  that  establishes  a  continuity 
between  the  central  termini  of  fibres,  is  not  merely  a  con- 
necting link:  it  is  also  a  reservoir  of  molecular  motion,  which 
it  gives  out  when  disturbed.  Hence,  if  the  composition  of 
nerve-centres  is  determined  as  above  indicated,  it  follows 
that  in  proportion  to  the  number,  extensiveness,  and  com- 
plexity, of  the  relations,  simultaneous  and  successive,  that 
are  formed  among  different  parts  of  the  organism,  will  be 
the  quantity  of  molecular  motion  which  the  nerve-centres 
are  capable  of  disengaging. 

§  13.  As  a  datum  for  Psychology  of  the  most  general 
kind,  the  foregoing  description  of  nervous  structure  might 
suffice.  But  having  to  deal  chiefly  with  that  more  special 
Psychology  distinguished  as  human,  it  will  be  proper  to  add 
some  account  of  the  human  nervous  system.  A  few  facts 
of  moment  respecting  its  peripheral  parts,  may  be  set  down 
before  we  study  its  central  parts. 

At  the  surface  of  the  body,  where  the  extremities  of 
nerve-fibres  are  so  placed  as  to  be  most  easily  disturbed,  we 
generally  find  what  may  be  called  multipliers  of  distur- 
4 


86  THE  DATA  OF  PSYCHOLOGY. 

bances.  Sundry  appliances  which  appear  to  have  nothing  in 
common,  have  the  common  function  of  concentrating,  on  the 
ends  of  nerves,  the  actions  of  external  agents.  That  this  is 
the  effect  produced  by  the  lenses  of  the  eyes,  is  a  familiar 
fact  It  is  a  less  familiar  fact  that  certain  otolites  and 
minute  rods  or  fibres,  immersed  in  a  liquid  contained  in  the 
internal  ear,  serve  to  transform  the  less  sensible  vibrations 
communicated  to  this  liquid,  into  the  more  sensible  vibrations 
of  solid  masses,  and  to  bring  these  directly  to  bear  on  the 
nerve-terminations.  So,  too,  is  it  over  the  integument;  or, 
at  any  rate,  over  the  parts  of  it  subject  to  many  and  varied 
contacts.  Though  men  have  not,  like  many  inferior  Mam- 
mals, the  well-developed  tactual  multipliers  called  vibrissm 
(known  in  a  cat  as  "  whiskers  "),  each  of  which  is  a  lever 
that  intensifies  a  slight  touch  at  the  outer  end  into  a  strong 
pressure  of  the  imbedded  end  upon  an  adjacent  nerve-fibre; 
yet  every  one  of  the  short  hairs  on  a  man's  skin  acts  in  the 
same  way.  And  then,  in  addition  to  these,  there  are,  at 
places  where  the  contacts  with  objects  are  perpetual,  and 
where  hairs  do  not  grow,  certain  multipliers  below  the  sur- 
face— small  dense  bodies  named  corpusoula  tactus^  round 
each  of  which  a  nerve-fibre  ramifies,  and  each  of  which, 
when  moved  by  the  touch  of  a  foreign  body,  gives  to  its  at- 
tached nerve-fibre  a  greater  pressure  than  this  would  receive 
were  the  surrounding  substance  homogeneous :  a  fact  which 
will  be  understood  on  remembering  the  effect  of  pressure  on 
the  skin  when  some  small  hard  body,  as  a  thorn,  is  imbed- 
ded in  it. 

So  much  for  the  instruments  that  are  external  to  the 
peripheral  expansions  of  the  nerves,  and  serve  to  exag- 
gerate the  effects  of  incident  forces.  We  may  now  con- 
template these  peripheral  expansions  themselves,  as  being 
adapted  to  receive  these  exaggerated  incident  forces. 
In  the  first  place,  the  ultimate  nerve-fibrillae,  ramifying 
where  they  are  most  exposed  to  disturbances,  consist  of 
nerve-protoplasm  unprotected  by  medullary  sheaths  and  not 


THE  STRUCTURE  OF  THE  NERVOUS  SYSTEM.         37 

even  covered  by  membranous  sbeatbs.  In  fact,  they  appear 
to  consist  of  matter  like  that  contained  in  nerve-vesicles, 
but  without  the  fat-granules;  and  may  be  regarded  as,  like 
it,  more  unstable  than  the  matter  composing  the  central 
fibres  of  the  fully-differentiated  nerve-tubes.  To  this  general 
character  of  the  nerve-terminations,  have  to  be  added  the 
more  special  characters  of  the  terminations  exposed  to 
special  forces.  The  delicate  pale  fibres  which  form  a  layer 
on  the  surface  of  the  retina,  are  not  directly  affected  by  the 
rays  of  light  concentrated  upon  them;  but  these  rays,  pass- 
ing through  them,  fall  on  a  layer  of  closely  packed,  but  quite 
'separate,  little  bodies  which  are  the  true  sensitive  structures; 
and  then  the  minute  nerve-fibrillse  that  run  from  these  to 
the  stratum  of  retinal  nerve-fibres,  pass  on  their  way  into  a 
layer  of  nerve-vesicles,  with  which  we  may  presume 
they  have  connections.  That  is  to  say,  this  peripheral 
expansion  of  the  nerve  on  which  visual  images  fall, 
contains  numerous  small  portions  of  the  highly-unstable 
nerve-matter,  ready  to  change,  and  ready  to  give  out 
molecular  motion  in  changing.  It  is  thus,  too,  with 
those  terminal  ramifications  of  the  auditory  nerve,  on  which 
sonorous  vibrations  are  concentrated.  And  there  is  an 
analogous  peculiarity  in  the  immensely-expanded  extremity 
of  the  olfactory  nerve.  Here,  over  a  large  tract  covered 
by  mucous  membrane,  is  a  thick  plexus  of  the  grey  un- 
sheathed fibres;  and  among  them  are  distributed  both 
nerve-vesicles  and  granular  grey  substance,  such  as  that  out 
of  which  the  vesicles  arise  in  the  nervous  centres. 

The  significance  of  these  structural  peculiarities  we  shall 
see  hereafter.  For  the  present  we  need  only  note  the  distri- 
bution of  them.  Over  the  skin,  which  is  conversant  with 
forces  of  a  relatively-considerable  intensity — mechanical 
impacts,  pressures,  tensions, — we  do  not  find  that  the  nerve- 
terminations  contain  deposits  of  the  peculiarly  unstable 
nerve-substance.  But  we  find  such  deposits  where  the 
incident  forces  are  extremely  feeble,  or  fall  on  excessively 


38  THE  DATA  OF  PSYCHOLOGY. 

small  areas,  or  both.  The  quantity  of  matter  which,  floating 
as  faint  odour  through  the  air,  reaches  the  end  of  the  ol- 
factory nerve,  is  infinitesimal.  Such  luminiferous  undula- 
tions as  are  allowed,  during  a  momentary  glance,  to  fall  on 
one  of  the  minute  areas  of  the  retina,  are  equivalent  to  a 
mechanical  force  inappreciable  by  our  measures,  if  not  in- 
expressible by  our  figures.  Similarly  with  those  atmo- 
spheric  waves  which,  produced  by  the  church-bell  a  mile 
away,  and  weakening  as  they  spread  in  all  directions,  are 
conveyed  to  the  minute  otolites  and  rods  of  the  inner  ear, 
to  be  by  them  impressed  on  the  auditory  nerves.  And  in 
these  places  it  is  that  we  find  peripheral  deposits  of  the 
specially-unstable  nerve-substance. 

§  14.  Arising  from  these  variously-specialized  peripheral 
structures,  the  afferent  nerves,  collected  into  their  bundles 
and  compound  bundles,  run  inwards  to  the  spinal  cord ;  out 
of  which  issue  the  corresponding  bundles  of  efferent  nerves. 
In  one  sense  the  spinal  cord  may  be  regarded  as  a  con- 
tinuous nervous  centre;  and,  in  another  sense,  as  a  series  of 
partially-independent  nervous  centres.  Each  pair  of  trunk 
nerves  with  its  segment  of  the  spinal  cord,  has  a  certain 
degree  of  individuality;  and  those  segments  into  which 
enter  the  pairs  of  massive  nerves  from  the  limbs,  have 
individualities  considerably  pronounced;  since  it  is  experi- 
mentally proved  that  when  severed  from  the  rest  they  are 
not  incapacitated.  The  tract  of  grey  matter  in  the  spinal 
cord  to  which  the  afferent  nerves  of  a  limb  come,  and  from 
which  the  efferent  nerves  issue,  is  practically  the  ganglionic 
centre  of  that  limb,  having  very  much  of  automatic  inde- 
pendence; and  being  joined  by  commissural  fibres  to  a 
like  centre  belonging  to  the  fellow  limb,  it  forms  with  this 
an  automatic  pair.  So  that,  remembering  how  the  entire 
cranio-spinal  axis  is  originally  one  and  continuous,  and  that 
its  anterior  part  has  been  differentiated  and  developed  into 
quite  distinct  centres  we  may  say  that  its  posterior  part,  the 


THE  STRUCTURE  OF  THE  NERVOUS  SYSTEM.        39 

spinal  cord,  lias  also  been  so  differentiated,  though  to  a 
mucli  smaller  extent.  To  this  conception  two 

additions  must  be  made.  Beyond  the  internal  tracts  of  grey 
or  vesicular  matter,  and  the  bundles  of  nerve-fibres  that 
enter  into  and  issue  from  them  laterally;  and  beyond  the 
transverse  commissural  fibres  which  connect  the  correspond- 
ing lateral  portions  of  grey  matter  or  partially-differentiated 
pairs  of  nervous  centres;  there  are  longitudinal  commissural 
fibres,  joining  these  successive  pairs  of  nervous  centres  with 
one  another,  and  serving  to  integrate  the  series  of  pairs  in 
the  same  way  that  the  members  of  each  pair  are  integrated. 
And  then,  along  with  these  fibres  that  unite  nervous  centres 
of  the  same  order,  there  are  what  we  found  it  desirable  to 
distinguish  as  centripetal  fibres,  running  from  the  relatively- 
inferior  nervous  centres  to  the  relatively-superior  ones; 
with  centrifugal  fibres  running  back. 

Of  these  relatively-superior  nervous  centres,  we  have  first 
to  notice  the  medulla  oblongata;  including  those  parts 
of  the  pons  Va/rolii  which  are  woven  into  it,  and  similarly 
arise  out  of  the  fourth  ventricle.  This  is  the  enlarged 
termination  of  the  spinal  cord,  lying  within  the  skull. 
Distinguished  as  it  is  from  lower  parts  of  the  spinal  cord  by 
its  greater  massiveness,  it  is  much  more  distinguished  by  the 
multiplicity  and  variety  of  its  peripheral  connections. 
While  the  successive  segments  of  the  spinal  cord  proper, 
have  pairs  of  afferent  and  efferent  nerves  which  are  limited 
in  their  distributions  to  particular  regions  of  the  body;  and 
while  even  such  an  entire  group  of  these  segments 
as  occupy  the  lumbar  region,  have  relations  only  with 
the  legs  and  the  lower  part  of  the  body;  the  medulla 
oblongata,  by  the  intermediation  of  centripetal  fibres,  is 
brought  into  relation  not  only  with  the  lower  part  of  the 
body  and  its  limbs,  but  with  the  upper  part  of  the  body  and 
its  limbs ;  and  not  only  with  these,  but  also  with  sundry  of 
the  parts  which  we  know  as  the  organs  of  the  special  senses; 
and  not  only  with  these,  but  also  with  the  more  important 


40  THE  DATA  OP  PSYCHOLOGY. 

viscera.  The  auditory  nerves  and  the  nerves  of  taste  go 
directly  into  it,  and  though  the  optic  nerves  do  not,  yet 
from  the  centres  to  which  they  run  there  are  fibres  communi- 
cating with  it;  from  its  laterally-appended  parts  arise  the 
nerves  of  the  eye-muscles  and  the  facial  nerves;  and  the 
pneumogastric  nerves,  given  off  from  its  posterior  part,  put 
it  in  communication  with  the  larynx,  the  lungs,  the  heart, 
the  liver,  and  the  stomach.  Respecting  its  connections,  direct 
and  indirect,  much  remains  to  be  ascertained;  but  what  is 
known  justifies  the  conclusion  that  the  medulla  oblongata^ 
including  the  structures  that  are  adnate,  is  a  portion 
of  the  originally-uniform  cerebro-spinal  axis,  which  has 
been  differentiated  into  a  centre  of  a  higher  order  than 
those  behind  it,  or  those  at  the  base  of  the  mass  in  front 
of  it — higher  in  the  sense  that  it  has  become  that  portion 
of  the  axis  in  which  centripetal  fibres  running  from  the 
posterior  ganglia,  and  from  some,  if  not  all,  of  the  anterior 
ganglia,  called  by  some  sensory,  are  brought  into  relation 
with  one  another — a  centre  through  which  these  local 
centres  are  united  into  one  system. 

Passing  over  with  a  mere  recognition  the  anterior  ganglia 
just  named,  the  exact  relations  of  which  are  ill-understood, 
but  some  of  which  comparative  morphology  proves  to  be 
portions  of  the  front  end  of  the  cerebro-spinal  axis  that 
have  become  differentiated  into  ganglia  of  the  first  order, 
receiving  those  special  external  stimuli  to  which  the  front 
end  of  the  body  is  exposed ;  there  remain  only  to  be  noticed 
the  two  great  bi-lobed  ganglia,  which  in  Man  form  the  chief 
mass  of  the  brain — the  cerebellum  and  the  cerebrum.  Phy- 
siologists and  anatomists  are  agreed  in  regarding  these  as 
centres  of  a  still  higher  order.  Anatomical  proof  of  their 
superiority,  as  being  the  seats  of  still  higher  centralization, 
is  very  incomplete ;  for  the  difficulty  of  tracing  the  courses 
of  all  the  nerve-fibres  that  enter  into  and  issue  from  them, 
has  hitherto  been  insuperable.  But  their  connections  with 
the  subjacent  minor  centres  and  with  the  medvUa  oblongatay 


THE  STRUCTURE  OF  THE  NERVOUS  SYSTEM.        41 

are  such  as  to  make  it  certain  that  through  the  intermedia- 
tion of  these,  they  communicate  with  the  whole  peripheral 
nervous  system;  and  are  places  in  which  centripetal  fibres 
from  centres  of  both  the  first  and  second  orders,  joined, 
possibly,  with  some  simply  afferent  fibres,  are  brought  into 
various  relations :  relations,  however,  that  most  likely  differ 
in  their  natures  from  those  established  in  inferior  centres — 
differ,  perhaps,  as  those  supposed  to  be  formed  in  the 
centre  II,  Fig.  4,  differ  from  those  formed  in  the  centre  F. 

Among  the  facts  of  fundamental  significance  with- which 
we  are  here  concerned,  one  other  may  be  named.  This 
concerns  the  histological  structures  of  nervous  centres.  la 
automatic  ganglia,  the  direct  union  of  nerve-fibres  with  nerve- 
cells  is  habitual.  Throughout  the  spinal  cord  the  "axis-cylin- 
ders "  may  not  unfrequently  be  traced  running  into  the 
vesicles.  But  in  the  higher  nerve-centres  direct  connections 
are  much  less  readily  made  out;  and  it  is  question- 
able whether  in  the  highest  they  occur  at  all.  In  the 
grey  substance  of  the  cerebrum,  the  delicate  nerve-fibres 
which,  divested  of  medullary  sheaths,  run  among  the  im- 
bedded corpuscles,  do  not  directly  unite  with  them;  or  if  it 
is  too  much  to  say  that  there  are  no  such  unions,  we  may 
say  that  they  are  rare.  Such  communications  as  exist  are 
apparently  between  the  branched  terminations  of  the  fibres 
and  the  ramified  processes  of  the  corpuscles.  Thus  at  the 
one  extreme,  simple,  clear,  and  complete  connections  are 
the  rule;  and  at  the  other  extreme,  involved,  vague,  and 
incomplete  connections. 

§  15.  Some  account  must  be  given  of  certain  remaining 
nervous  structures,  with  which  Psychology  is  indirectly 
concerned.  Thus  far  we  have  dealt  only  with  the  fibres  and 
centres  that  stand  passively  and  actively  related  to  the  ex- 
ternal world;  but  there  are  fibres  and  centres  that  stand 
related  to  those  internal  organs  which  make  possible  the 
continuance  of  relations  to  the  external  world. 


42  THE  DATA  OP  PSYCHOLOGY. 

The  first  to  claim  attention  are  the  vaso-motor  nerves. 
Bundles  of  these  issue  from  the  spinal  cord,  and,  joined  by 
bundles  of  nerves  arising  from  the  sympathetic  system,  ac- 
company the  main  arteries:  dividing  and  subdividing  wher- 
ever these  do,  so  as  to  supply  fibres  to  all  their  branches  down 
to  the  most  minute.  The  vaso-motor  nerves  form,  in  fact, 
an  additional  series  of  efferent  nerves.  The  nervous  arc 
imder  its  lowest  form,  consists  of  the  afferent  nerve  with  its 
peripheral  extremity  exposed  to  external  actions,  the  gan- 
glion-corpuscle to  which  its  central  extremity  runs,  and  the 
efferent  nerve  thence  issuing  to  end  in  some  muscle.  But 
as  we  have  seen,  the  unit  of  composition  of  the  developed 
nervous  system,  includes  a  centripetal  fibre,  running  from 
the  first  or  subordinate  centre  to  a  higher  centre;  and  here 
we  have  to  add,  as  an  habitual  element  of  this  unit  of 
composition  in  its  complete  form,  a  vaso-motor  fibre, 
running  to  that  part  of  the  body  in  which  the  two  ends 
of  the  nervous  arc  lie,  and  bringing  the  blood-vessels 
of  that  part  into  relation  with  the  other  parts  of  the 
apparatus. 

The  cerebro-spinal  nervous  system,  besides  having  these 
direct  communications  with  the  muscular  walls  of  the  tubes 
which  bring  blood,  both  to  itself  and  to  the  muscles  it  sends 
fibres  to,  is  also  put  into  relation  with  other  parts  on 
which  it  is  equally,  though  less  immediately,  dependent — 
the  viscera.  These  have,  indeed,  a  nervous  system  of  their 
own,  possessing  apparently  a  considerable  degree  of  inde- 
pendence— the  sympathetic  system;  and  one  all-important 
viscus,  the  heart,  has  a  nervous  system  that  is  demonstrably 
independent.  The  morphological  interpretation  of  the  vis- 
ceral nervous  system  is  not  settled;  but  whether  it  has  a 
separate  origin,  or  belongs  to  the  periphery  of  the  cerebro- 
spinal system,  the  undoubted  fact  is  that  the  cerebro-spinal 
system,  through  the  nerves  running  from  it  into  the 
trunks  of  the  sympathetic,  communicates  with  all  these  vital 
organs;  and  that  even  the  heart,  complete  as  is  its  local 


THE  STRUCTURE  OF  THE  NERVOUS  SYSTEM.        43 

nervous  system,  is,  by  the  vagus  or  pneumogastric  nerve, 
integrated  with  the  cerebro-spinal  system. 

A  more  particular  account  of  these  and  sundry  structures 
of  the  same  class  is  not  necessary  here.  The  general  fact  of 
significance  for  us,  is,  that  the  brain  and  spinal  cord  which 
through  their  afferent  nerves  are  put  in  relation  with  the 
actions  of  the  external  world,  and  which  through  their 
efferent  nerves  are  put  in  relation  with  the  structures  that 
react  on  the  external  world,  are  also  put  in  relation  with 
the  organs  immediately  or  remotely  instrumental  in  supply- 
ing them  with  nutriment,  and  removing  the  effete  matters 
resulting  from  their  activities. 

§  16.  In  the  foregoing  description  I  have  endeavoured  to 
include  all  that  Psychology  needs.  Many  conspicuous 
traits  of  nervous  structure  which  some  will  think  ought  to 
be  set  down,  are  really  altogether  irrelevant.  That  in  the 
spinal  cord  the  gray  matter  is  placed  internally,  while  in  the 
cerebrum  it  forms  an  outside  stratum,  is  a  fact  of  moment 
in  anatomy,  but  one  which  throws  no  light  on  the  science  of 
mind.  Knowledge  of  the  truth  that  the  posterior  roots  of 
the  spinal  nerves  are  afferent,  while  the  anterior  are  efferent, 
is  all-important  to  the  pathologist;  but  to  the  psychologist 
it  is  quite  unimportant,  since  this  arrangement  might  have 
been  reversed  without  the  principles  of  nervous  structure 
being  in  the  least  changed;  and  it  is  with  these  principles 
only  that  the  psychologist  is  concerned.  The  leading  facts 
embodying  these  principles  may  be  summed  up  thus: — 

The  three  great  sub-kingdoms  of  animals  in  which  the 
nervous  system  becomes  considerably  evolved,  show  us  that 
along  with  the  relatively-increased  massiveness  distinguish- 
ing the  higher  types  of  the  nervous  system,  there  goes  that 
other  kind  of  integration  implied  by  increase  of  structural 
combination.  There  is  multiplication  and  enlargement  of 
the  parts  that  unite  local  nervous  centres  with  general 
nervous  centres.    Very  frequently  there  is  an  approach  or 


44  THE  DATA  OF  PSYCHOLOGY. 

clustering  of  nervous  centres  that  were  previously  far  apart. 
And  there  is  both  a  relative  and  an  absolute  increase  in 
those  centres  which  have  the  most  multiplied  relations  with 
local  centres,  and  through  them  with  all  parts  of  the  body. 

The  nervous  system  is  made  up  of  threads  inclosed  in 
sheaths,  and  corpuscles  imbedded  in  protoplasm;  of  which 
the  threads,  united  into  bundles,  constitute  almost  the  whole 
of  the  peripheral  parts,  while  the  corpuscles  with  their  matrix 
are  found  chiefly  in  the  central  parts.  Having  at  its  outer 
extremity  a  plexus  of  highly-unstable  matter,  a  nerve-thread, 
consisting  as  we  conclude  of  less  unstable  matter  but 
matter  isomerically  transformed  with  ease,  runs  inwards, 
surrounded  by  substances  that  shield  it  from  lateral  distur- 
bance. Eventually  it  reaches  a  mass  of  highly  unstable 
matter,  so  conditioned  as  to  undergo  decomposition  with  the 
greatest  facility;  and  from  the  place  where  this  lies  there 
run  other  like  fibres  to  other  masses  of  unstable  matter,  of 
the  same  kind,  or  of  a  different  kind,  or  both — here  to  a 
portion  of  substance  that  contracts  when  disturbed,  and 
here  to  a  superior  centre  containing  more  of  the  easily-de- 
composed nerve-substance.  These  threads,  afferent,  efferent, 
and  centripetal,  with  their  connecting  corpuscle  or  portion 
of  grey  matter,  we  regard  as  forming  the  unit  of  composi- 
tion of  the  nervous  system. 

Such  units  are  variously  grouped  and  combined.  Each 
local  ganglion  is  a  place  where  many  afferent  and  many 
efferent  nerves  are  connected  by  many  portions  of  the  un- 
stable nerve-matter,  capable  of  suddenly  giving  out  much 
molecular  motion.  Each  superior  ganglion  is  a  place  where 
centripetal  and  centrifugal  fibres  from  such  local  or  inferior 
ganglia,  are  similarly  connected  by  similar  matter.  And  so 
with  still  higher  ganglia  in  their  relations  to  these.  Erom 
which  principle  of  combination  it  results  that  the  possibili- 
ties of  different  compound  relations  increase  as  fast  as  the 
centralization  progresses. 

We   saw,   however,    that   this   establishment   of   more 


THE  STRUCTURE  OF  THE  NERVOUS  SYSTEM.         45 

numerous,  more  involved,  and  more  varied  relations  among 
the  parts  of  the  organism,  implies  not  simply  this  grouping 
of  fibres  and  this  arrangement  of  centres;  but  also  a  mul- 
tiplication of  the  nerve-corpuscles,  or  portions  of  grey 
matter,  occupying  their  centres.  And  we  found  it  to  follow 
that  where  the  compound  relations  formed  are  among  many 
points,  or  where  the  points  are  to  be  combined  in  many  or- 
ders, or  both,  great  accumulations  of  grey  matter  are  needed : 
an  important  corollary  being  that  the  quantity  of  this  matter 
capable  of  giving  out  much  motion,  increases  in  proportion 
as  the  combinations  formed  become  large  and  heterogeneous. 

Passing  to  the  special  nervous  structure  related  to  that 
special  Psychology  of  chief  importance  to  us,  we  saw 
that  the  spinal  cord  is  a  series  of  partly  dependent,  partly 
independent,  double  nerve-centres;  each  concerned  with  a 
particular  portion  of  the  trunk  or  a  particular  limb,  to  the 
skin,  muscles,  and  vessels  of  which  it  sends  nerves. 
The  enlarged  cephalic  extremity  of  the  spinal  cord,  the 
meduUa  oblongata^  is  a  centre  connected  by  centripetal 
fibres  with  these  partially-differentiated  inferior  centres; 
and  receiving,  as  it  also  does,  diiectly  or  indirectly,  nerves 
from  the  special  sense-organs,  the  medulla  oblongata  is  a 
centre  where  the  local  centres  concerned  with  nearly  all  parts 
of  the  body,  are  brought  into  communication.  We  saw,  last- 
ly, that  the  two  great  bi-lobed  masses  overlying  the  medulla 
oblongata  and  the  sensory  ganglia,  with  which  they  are  in- 
timately connected,  may  be  regarded  as  centres  in  which 
these  compound  connections  are  united  into  connections  still 
more  compound,  still  more  various,  and  still  more  numerous. 

One  further  fact  which  it  remained  for  us  to  note,  was 
that  while  the  more  important  nervous  structures  are  those 
which  bring  the  parts  that  are  acted  upon  by  the  outer 
world,  into  relation  with  the  parts  that  react  upon  it,  there 
are  also  nervous  structures  that  bring  all  these  into  relation 
with  the  vital  organs:  so  serving  to  unite  the  parts  which 
expend,  with  the  parts  which  accumulate  and  distribute. 


CHAPTER  HL 

THE   FITNOTIONS   OF   THE   NEBVOUS   SYSTEM. 

§  lY.  When,  at  the  outset,  we  inquired  what  are  the 
manifestations  with  which  the  nervous  system  is  associated, 
we  necessarily,  in  drawing  a  conclusion,  asserted  in  general 
terms  the  part  performed  by  the  nervous  system.  And 
though  in  the  chapter  just  ended  the  sole  aim  has  been 
to  describe  nerve-threads,  nerve-cells,  nerve-trunks,  nerve- 
centres,  and  the  ways  in  which  they  are  put  together;  yet 
the  ends  subserved  have  unavoidably,  from  time  to  time, 
come  into  view.  Structure  and  function  are  in  our  thoughts 
80  intimately  related,  that  it  is  scarcely  possible  to  give  a 
rational  account  of  the  one  without  some  tacit  reference  to 
the  other.  Here,  however,  function  is  to  be  our  special 
topic.  Having  seen  how  the  nervous  system  is  constructed, 
we  have  now  to  see  how  it  works. 

The  proposition  with  which  the  first  chapter  ended  was 
that  nervous  evolution  varies  partly  as  the  quantity  of 
motion  generated  in  the  organism,  and  partly  as  the  com- 
plexity of  this  motion.  Here  the  initial  inquiry  must  be, 
how  the  nervous  system  serves  as  at  once  the  agent  by  which 
motions  are  liberated  and  the  agent  by  which  motions  are 
co-ordinated.  Three  things  have  to  be  explained : — 1.  What 
are  the  causes  which  on  appropriate  occasions  determine 

the  nervous  system  to  set  up  motion?    2.  By  what  process 

46 


THE  FUNCTIONS  OF  THE  NERVOUS  SYSTEM.        47 

does  it  liberate  the  insensible  motion  locked  up  in  certain 
tissues,  and  cause  its  transformation  into  sensible  motion? 
3.  How  does  it  adjust  sensible  motions  into  those  com- 
binations, simultaneous  and  successive,  needful  for  efficient 
action  on  the  external  world?  These  questions  cover  the 
whole  of  its  functions;  or,  at  any  rate,  all  those  of  its 
functions  with  which  we  are  directly  concerned.  We  have 
to  interpret  its  passive  function  as  a  receiver  of  disturbances 
that  set  it  going;  its  active  function  as  a  liberator  of  mo- 
tion; and  its  active  function  as  a  distributor  or  apportioner 
of  the  motion  liberated. 

Probably  it  will  be  thought  that  there  is  here  introduced 
a  function  distinct  from  those  before  named.  It  seems  that 
the  receiving  of  disturbances,  or  stimuli,  can  be  included 
neither  under  the  head  of  disengaging  motions  nor  under  the 
head  of  co-ordinating  motions.  But  on  reducing  the  facts 
to  their  lowest  terms,  and  to  those  terms  which  Physiology 
proper  can  alone  recognise,  the  difficulty  disappears.  For 
all  nervous  stimuli  are  motions,  molar  or  molecular;  and 
the  function  of  co-ordinating  motions  comprehends  not 
simply  the  combining  and  apportioning  of  the  motions  ex- 
pended, but  also  the  combining  of  the  motions  received, 
and  the  adjustment  of  the  one  set  into  harmony  with  the 
other.  A  moment's  thought  justifies  this  proposition.  The 
stimuli  to  the  nerves  of  touch  are  sensible  motions  of  the 
imbedding  tissue,  caused  either  by  the  impacts  of  external 
moving  bodies  or  by  motions  of  the  organism  which  bring 
it  against  external  bodies,  fixed  and  moving.  The  auditory 
nerve  receives  the  motions  conveyed  to  it  from  masses  of 
matter  that  are  vibrating.  Those  minute  agents  that  termi- 
nate the  nerves  of  the  retina  are  acted  on  by  luminiferous 
undulations — motions  of  the  ethereal  medium  which  pro- 
duce motions  among  their  molecules.  So,  too,  the  nerves 
excited  by  sapid  and  odorous  substances,  are,  in  fact,  excited 
by  the  molecular  movements  these  substances  cause  in  their 
extremities  by  chemically  changing  them.    Thus,  speaking 


48  THE  DATA  OP  PSYCHOLOGY. 

not  figuratively  but  literally,  an  afferent  fibre  of  whatever 
kind  is  a  recipient  of  motion  given  to  its  molecules:  either 
by  molar  motion,  as  when  a  blow  is  received;  or  by  the 
motion  of  other  molecules,  as  when  there  is  contact  with 
a  chemically-active  body;  or  by  those  ethereal  molecular 
motions  which  constitute  radiant  heat  and  light. 

It  will  be  well  to  consider  more  fully  this  sub-division 
of  nervous  functions,  and  the  reasons  for  here  proceeding 
upon  it. 

§  18.  Physiology  is  an  objective  science;  and  is  limited 
to  such  data  as  can  be  reached  by  observations  made  on 
sensible  objects.  It  cannot,  therefore,  properly  appropriate 
subjective  data;  or  data  wholly  inaccessible  to  external 
observations.  Without  questioning  the  truth  of  the  as- 
sumed correlation  between  the  changes  which,  physically 
considered,  are  disturbances  of  nerves,  and  those  which, 
psychically  considered,  are  feelings;  it  may  be  safely  affirmed 
that  Physiology,  which  is  an  interpretation  of  the  physical 
processes  that  go  on  in  organisms,  in  terms  known  to 
physical  science,  ceases  to  be  Physiology  when  it  imports 
into  its  interpretations  a  psychical  factor — a  factor  which 
no  physical  research  whatever  can  disclose,  or  identify,  or 
get  the  remotest  glimpse  of.  The  relations  between  nerve- 
actions  and  mental  states  form  a  distinct  subject,  to  be 
dealt  with  presently.  Here  we  are  treating  of  nerve-ac- 
tions on  their  physiological  side,  and  must  ignore  their 
psychological  side. 

Doing  this,  we  have  no  alternative  but  to  formulate  them 
in  terms  of  motion.  And  having  recognized  the  primary 
division  to  be  that  between  the  liberation  of  motions  and 
the  co-ordination  of  motions,  we  find  that  this  last  division 
must  be  sub-divided.  It  includes,  first,  the  co-ordination 
of  the  motions  received  with  one  another;  and,  second,  the 
co-ordination  of  the  motions  expended  with  the  motions 
received,  and  with  one  another.    Hence  results  a  generalized 


THE  FUNCTIONS  OP  THE  NERVOUS  SYSTEM.         49 

idea  of  nervous  functions,  as  divisible  into  recipio-motorj 
Hhero-motor,  and  dirigo-motor. 

It  must  be  admitted  that  in  their  higher  forms,  these 
functions  are  so  entangled  that  a  tripartite  division  of  them 
is  difficult,  if  not  impossible.  To  the  simplest  types  of 
nervous  structure,  the  classification  is  easily  applied:  each 
afferent  nerve  is  a  reGipio^motor  agent ;  each  ganglion  is  a 
libero-nwtor  agent;  each  efferent  nerve  is  a  dirigo-motor 
agent.  But  in  complex  nervous  systems,  formed  of  inferior 
and  superior  centres  connected  by  parts  containing  nerves 
that  are  centripetal,  centrifugal,  and  commissural,  there  arise 
corresponding  secondary  functions  which  greatly  obscure 
the  primary  functions.  It  remains  true  that  all  the  afferent 
nerves  are  receivers  of  motions,  and  that  all  the  efferent 
nerves  are  directors  of  motions;  and  it  remains  true  that 
the  vesicles  and  portions  of  grey  substance  throughout  the 
centres  are  liberators  of  motions;  but  of  the  fibres  largely 
composing  these  centres  we  must  say  that  their  functions 
are  both  receptive  and  directive.  ^N^evertheless,  we  shall 
be  considerably  helped  by  thinking  of  the  afferent  nerves 
as  redpio-motor  and  the  efferent  nerves  as  dirigo-motor  / 
while  we  think  of  the  nervous  centres  as  composed  of  Ubero- 
motor  elements  along  with  elements  that  perform  both  the 
other  functions. 

This  general  conception  has  now  to  be  made  specific. 
In  dealing  with  functions  we  will  follow  the  same  order  as 
we  did  in  dealing  with  structures — we  will  consider  first  the 
offices  of  the  different  kinds  of  nervous  matter. 

§  19.  The  grey  substance  and  the  white  substance — or, 
to  speak  more  strictly,  the  nitrogenous  matter  in  and  around 
the  vesicles  and  the  nitrogenous  matter  occupying  the 
centres  of  the  nerve  tubes — have  not  absolutely  distinct 
duties.  Certain  simple  animals  yield  evidence  that  in  the 
rudimentary  nervous  system,  there  is  no  such  structural 
differentiation  and  consequently  no  such  functional  differ- 


50  THE  DATA  OP  PSYCHOLOGY. 

entiation;  and  there  is  proof  that  even  in  the  highest  ani- 
mals the  differentiation  is  incomplete. 

On  the  one  hand  the  vesicular  substance,  having  for  its 
chief  office  to  give  out  molecular  motion  when  disturbed, 
has  also  a  considerable  power  of  conveying  or  conducting 
molecular  motion.  When  the  fibrous  parts  of  the  spinal 
cord  have  been  cut,  it  is  found  that  if  the  central  columns  of 
grey  matter  remain  uncut,  or  if  there  remains  even  a  narrow 
link  to  maintain  the  continuity  of  the  grey  matter,  disturb- 
ance is  still  communicated  through  it  to  the  brain:  not,  in- 
deed, disturbance  of  any  special  kind,  but  disturbance  of  the 
most  general  kind.  True,  it  does  not  follow  that  such  dis- 
turbance passes  along  the  grey  matter  from  end  to  end. 
Throughout  the  whole  length  of  the  spinal  cord,  nerve-fibrea 
divested  of  their  medullary  sheaths  enter  into  and  afterwards 
issue  from  the  grey  matter;  and,  again  protected  by  their 
sheaths,  proceed  upwards  to  the  brain  in  the  surrounding 
white  matter.  Very  likely  these  take  up  and  convey  molecu- 
lar disturbances  set  up  in  the  grey  matter  imbedding  them. 
But  even  this  implies  that  disturbances  are  propagated  to 
some  extent  through  the  grey  matter;  and  the  argument  re- 
quires no  more. 

Conversely,  it  is  found  that  the  matter  forming  the  "  axis- 
cylinder,"  or  essential  nerve-thread,  can  do  something 
more  than  transmit  molecular  motion.  It  has  a  certain 
power  of  simultaneously  giving  out  molecular  motion: 
so  sharing  the  property  of  the  vesicular  matter.  When 
a  nerve  is  irritated  not  far  above  its  termination  in  a 
muscle,  the  effect  is  but  small.  If  the  irritation  is  at  a  point 
further  removed  from  the  muscle,  the  effect  is  greater.  And 
flie  effect  increases  as  the  length  of  nerve  through  which  the 
disturbance  is  conveyed  increases.  From  this  we  must  infer 
that  besides  the  molecular  motion  received  and  transferred, 
there  is  molecular  motion  liberated  in  the  nerve-fibre  itself. 
Not  that  this  molecular  motion,  like  that  which  the  vesicular 
matter  yields  up,  implies  an  equivalent  decomposition.    Pre 


THE  FUNCTIONS  OF  THE  NERVOUS  SYSTEM.         51 

bablj  it  is  a  concomitant  of  the  isomeric  transformation 
propagated  through  a  disturbed  nerve,  and  serving  to  con- 
vey the  disturbance.  Some  such  accompanying  result  is  to 
be  inferred,  d priori,  if  the  conduction  is  effected  by  isomeric 
transformation,  or  by  any  kind  of  molecular  re-arrangement. 
When  the  molecules  of  a  mass  change  from  one  form  of 
combination  to  another,  either  absorption  or  liberation  of 
motion  is  sure  to  occur.  That  there  cannot  in  this  case 
be  absorption  of  motion  is  manifest;  since  that  would  in- 
volve a  proportionate  resistance  to  the  transfer — the  amount 
of  force  or  motion  received  by  the  extremity  of  the  nerve, 
would  quickly  be  used  up  in  transforming  the  adjacent  part 
of  the  nerve,  and  the  change  would  travel  but  a  little  way. 
Being  thus  obliged  to  infer  that  motion  is  liberated,  we  at 
once  see  whence  nerve-fibre  derives  the  power  to  increase 
the  disturbance  it  conveys;  since  each  portion,  while  passing 
on  the  wave  of  molecular  motion,  adds  the  molecular  motion 
given  out  during  its  own  transformation.  This  action  may 
be  rudely  symbolized  by  the  transfer  of  sensible  motion 
along  a  row  of  bricks  on  end,  so  placed  that  each  in  falling 
knocks  over  its  neighbour.  For  if  instead  of  bricks  which 
stand  on  tolerably  broad  ends  and  require  some  force  to 
overturn  them,  we  suppose  bricks  that  are  delicately 
balanced  on  narrow  ends;  and  if  we  further  suppose  them 
so  constituted  that  they  do  not  dissipate  motion  by  per- 
cussion or  friction;  we  shall  see  that  the  motion  transmitted 
will  accumulate.  Each  brick,  besides  the  motion  it  re- 
ceives, will  pass  on  to  the  next  the  motion  which  it  has 
itself  gained  in  falling. 

The  general  truths  to  be  carried  with  us  are,  that  in  its 
primordial  undiiferentiated  state,  nerve-matter  unites  the 
properties  of  giving  out  molecular  motion  and  convey- 
ing molecular  motion;  but  that  with  the  advance  of 
evolution,  it  becomes  specialized  into  two  kinds,  of  which 
the  one,  collected  together  in  masses,  has  mainly  the  function 
of  giving  out  motion,  though  it  can  still  to  some  extent  con- 
5 


62  THE  DATA  OF  PSYCHOLOGY. 

duct  it,  while  the  other,  collected  together  in  threads,  has 
mainly  the  function  of  conducting  motion,  though  it  can 
still  to  some  extent  give  it  out. 

§  20.  The  co-operation  of  these  differentiated  kinds  of 
nerve-substance,  having  differentiated  functions,  is  seen  in 
its  simplest  form  where  they  are  combined  into  what  was 
before  described  as  the  unit  of  composition  of  the  nervous 
system.  An  afferent  nerve,  changed  by  a  touch  at  its  outer 
end,  and  traversed  by  a  wave  of  isomeric  transformation  that 
gathers  strength  as  it  goes,  communicates  this  wave  to  the 
comparatively  large  mass  of  unstable  matter  connected  with 
its  inner  end.  The  shock  of  molecular  disturbance,  im- 
mensely increased  by  the  decomposition  set  up  in  this 
unstable  matter  constituting  a  ganglion-corpuscle  or  its 
matrix,  diffuses  itself  around,  but  takes  mainly  the  shape  of 
a  relatively-powerful  wave  of  isomeric  transformation  along 
the  efferent  nerve.  And  the  efferent  nerve  being  distributed 
at  its  other  end  among  the  fibres  of  a  muscle,  this  powerful 
wave  sets  up  in  them  an  isomeric  transformation  of  another 
kind,  resulting  in  contraction  (^Primcvples  of  Biology^  §  303). 

The  belief  that  these  are  the  offices  of  the  respective  parts, 
is  borne  out  by  those  peculiarities  of  structure  which  were 
described  as  occurring  in  the  afferent  fibres  of  certain 
special  sense-organs.  We  saw  that  the  outer  ends  of  the  optic 
nerve,  the  auditory  nerve,  and  the  olfactory  nerve,  are  alike 
characterized  by  the  presence  of  vesicular  matter;  and  that 
while  in  this  they  differ  from  the  outer  ends  of  the  nerves 
of  touch,  they  also  differ  in  being  excessively  sensitive.  If 
grey  matter,  or  the  matter  of  vesicles,  has  the  function  of 
immensely  multiplying  any  molecular  motion  it  receives, 
and  passing  on  the  augmented  wave  of  change  along  con- 
nected fibres,  we  at  once  have  a  satisfactory  explanation  of 
these  peculiar  peripheral  structures.  Take  as  an  example  the 
retina.  One  of  the  minute  cones  in  its  sensitive  layer, 
measuring  not  -nrJinr*^  ^^  *°  \n<^  in  diameter,  has  its  com- 


THE  FUNCTIONS  OF  THE  NERVOUS  SYSTEM.         53 

ponent  matter  changed  by  the  etherial  vibrations  emanating 
from  a  candle  in  a  cottage-window  at  a  great  distance.  The 
infinitesimal  impact  received  from  so  faint  a  ray,  may  well 
be  supposed  insufiicient  to  send  through  a  considerable  length 
of  afferent  nerve,  an  adequately-rapid  wave  of  molecular 
change ;  but  this  wave,  after  passing  through  an  extremely 
delicate  fibril  less  than-j-Ji^of  an  inch  in  length,  comes  to  a 
layer  of  ganglion-corpuscles,  with  one  of  which  we  may 
presume  that  it  unites.  In  this  the  minute  disturbance  sets 
up  destructive  molecular  change — unlocks  a  considerable 
amount  of  molecular  motion;  and  thus  greatly  augmented, 
the  wave  of  transformation  traverses  the  remainder  of  the 
afferent  nerve  without  that  loss  of  time  that  would  result 
had  it  to  gain  strength  by  a  series  of  increments,  starting 
from  an  infinitesimal  first  term. 

How  such  appliances  for  multiplying  action  co-operate 
in  these  cases  where  the  initial  action  is  excessively 
minute,  may  be  illustrated  by  certain  artificial  appli- 
ances that  co-operate  in  an  analogous  manner.  A  man 
with  a  hair-trigger  pistol  in  his  hand,  puts  its  muzzle  to 
the  end  of  a  train  that  runs  to  a  powder-magazine.  The 
slightest  pressure  on  the  trigger  liberates  a  spring,  and 
this  drives  down  the  hammer.  Here  is  something  like  the 
external  multiplier  which,  as  we  have  seen,  habitually 
intensifies  the  action  that  falls  on  the  end  of  an  afferent 
nerve.  The  propelled  hammer  explodes  the  unstable 
detonating  powder  in  the  cap;  thus  playing  a  part  com- 
parable to  that  of  the  concentrated  pencil  of  light,  which 
causes  decomposition  in  one  of  the  minute  sensitive  rods  or 
cones  of  the  retina.  The  explosion  of  the  cap  explodes  the 
powder  in  the  pistol:  a  change  that  may  symbolize  the 
setting  up  of  decomposition  in  an  adjacent  ganglion-cell  by 
a  disturbed  retinal  element.  The  flash  from  the  mouth  of 
the  pistol  fires  the  train,  which,  carrying  the  flame  onwards, 
blows  up  the  magazine;  and  this  serves  to  illustrate  the 
action  of  the  partially-decomposed  ganglion-cell  which  pro- 


54  THE  DATA  OF  PSYCHOLOGY. 

pagates  a  shock  through  the  afferent  nerve  to  a  large  de- 
posit of  unstable  matter  in  the  optic  centre,  where  an  im- 
mense amount  of  molecular  motion  is  thereupon  disengaged. 
The  joint  action  of  an  afferent  fibre,  its  centrally-seated 
ganglion-corpuscle,  and  the  connected  efferent  fibre,  is  com- 
monly known  as  a  reflex  action.  The  name  indicates  the 
general  truth  that  the  disturbance  in  travelling  from  its  place 
of  origin  to  the  place  where  its  effect  is  seen,  passes  through 
a  point  at  which  its  course  is  bent  or  reflected;  and  in  so  far 
as  it  describes  this  very  general  trait  the  term  is  a  good 
one.  But  if  the  foregoing  interpretation  be  correct,  the 
term  is  in  other  respects  objectionable.  On  the  one  hand,  it 
implies  as  essential  what  is  non-essential.  That  the  wave 
of  disturbance  makes  a  sudden  turn  at  one  part  of  its 
course,  is  a  fact  of  no  intrinsic  moment — is  merely  a  con- 
comitant of  the  fact  that  the  nerves  it  traverses  have  to  be 
put  in  communication  with  other  nerves,  and  that  points  of 
junction  imply  angles.  On  th^  other  hand,  it  leaves 
out  of  sight  the  fact  that  one  of  these  points  of  junction 
from  which  the  wave  of  disturbance  is  said  to  be  reflected, 
is  a  place  at  which  it  is  greatly  augmented;  and  that  this 
augmentation  of  the  wave  is  the  all-important  oflice  of  the 
matter  lying  at  the  point  of  junction. 

§  21.  Remembering  that  bundles  of  such  afferent  nerves 
are  joined  to  bundles  of  such  efferent  nerves,  by  clusters  of 
such  corpuscles  imbedded  in  the  grey  matter  of  a  ganglion, 
and  that  bundles  of  centripetal  nerves  proceed  thence  to 
higher  ganglia;  we  have  next  to  consider  the  functions  of 
these  structures  as  wholes. 

A  nervous  centre,  even  of  an  inferior  order,  is  not  simply 
a  place  where  afferent  nerves  are  severally  linked  with  their 
corresponding  efferent  nerves,  by  corpuscles  or  portions  of 
grey  matter  that  multiply  and  pass  on  disturbances;  nor 
is  the  only  further  office  it  serves  that  of  sending  to  higher 
ganglia,  portions  of  these  disturbances;    but  it  is  also  a 


THE  FUNCTIONS  OF  THE  NERVOUS  SYSTEM.         55 

place  where  more  involved  communications  are  effected. 
For  in  all  ganglia  save,  perhaps,  the  very  simplest, 
the  corpuscles  or  vesicles  give  off  processes  more  or  less 
numerous,  and  usually  more  or  less  branched;  and  these 
branched  processes,  spreading  through  the  matrix  of  grey 
matter,  may  be  assumed  to  propagate  in  various  directions, 
and  various  degrees,  the  disturbance  set  up  in  the  corpuscle. 
This  diffusion  of  liberated  molecular  motion  has  two  im- 
plications. First,  the  number  and  complexity  of  the  cor- 
related changes  produced  by  the  original  change,  increase 
with  the  multiplication  and  variety  of  these  processes  and 
their  connexions.  And,  second,  along  with  increase  in  the 
number  of  correlated  changes,  there  goes  increase  in  the 
total  quantity  of  molecular  motion  given  out,  directly  or 
indirectly. 

Fully  to  understand  the  importance  of  this  last  implica- 
tion, it  is  needful  to  refer  back  to  Fig.  4,  and  to  the  accom- 
panying description  of  the  way  in  which  a  nervous  centre 
that  serves  to  establish  the  various  possible  relations  among 
different  points  in  an  organism,  must  contain  a  large  accu- 
mulation of  these  connecting  and  multiplying  links;  and 
where  it  was  shown  how  immense  must  become  the  accumu- 
lation of  vesicular  matter  in  a  centre  that  has  the  office  of 
establishing  relations  among  thesa  many  parts  in  various 
orders.  For  it  will  be  seen  that  as  fast  as  the  connexions 
become  numerous  and  complex,  so  fast  will  enlarge  the 
crowds  of  these  connecting  corpuscles  and  multipliers  of 
disturbance  which  simultaneously  come  into  action.  And 
hence  the  quantity  of  molecular  motion  evolved  in  the 
nervous  centres  will  become  great  in  proportion  as  the 
nervous  relations  increase  in  integration  and  heterogeneity. 

When  we  see  how  the  arrangements  for  liberating  and 
multiplying  motion,  described  under  their  simple  form  in 
the  last  section,  are  thus  compounded — when,  recurring  to 
our  simile,  we  see  how  the  first  central  magazine  of  force 
exploded,  communicates  with  other  larger  magazines,  and 


56  THE  DATA  OP  PSYCHOLOGY. 

these  again  with  still  larger,  which  are  subsequently  ex- 
ploded; we  shall  be  at  no  loss  to  understand  how  the 
slightest  impression  on  one  of  the  recipio-motor  nerves, 
may  evoke  from  the  Uhero-motor  centres  a  relatively-in- 
commensurable amount  of  force,  which,  discharged  along 
the  dirigo-motor  nerves,  may  generate  violent  muscular 
contractions.  So  that,  to  take  a  case,  a  slight  sound  may 
produce  a  convulsive  start  of  the  whole  body;  or  an  un- 
expected motion  of  some  adjacent  object,  infinitesimal  as  is 
the  modification  it  produces  in  the  retina,  may  neverthe- 
less cause  an  involuntary  jump  and  scream. 

§  22.  In  treating  nervous  functions  in  general,  I  have 
unawares  ended  with  illustrations  from  the  nervous  func- 
tions of  human  beings:  so  coming  to  the  division  of  the 
subject  on  which  we  have  next  to  enter.  For  the  brief 
account  given  in  the  last  chapter  of  the  special  nervous 
structures  with  which  we  are  most  concerned,  must  here  be 
supplemented  by  a  brief  account  of  their  special  functions. 

If  we  leave  out  such  afferent  and  efferent  fibres  as  pass 
through  the  spinal  cord  to  and  from  the  encephalon,  and  also 
those  centripetal  and  centrifugal  fibres  which  connect  its 
.various  parts  with  the  eticephalon,  we  may  regard  the  partly 
dependent  and  partly  independent  centres  composing  the 
spinal  cord,  as  being  co-ordinators  of  the  actions  performed 
by  the  skin  and  muscles  of  the  trunk  and  limbs.  A  large 
proportion  of  these  actions,  including  many  of  considerable 
complexity,  the  spinal  cord  is  able  to  co-ordinate  without 
aid  from  the  higher  centres;  and  some  of  the  partially- 
differentiated  centres  composing  the  spinal  cord,  are  able  to 
effect  simple  co-ordinations  without  aid  from  the  rest.  We 
will  glance  at  these  simple  co-ordinations  first.  If 

a  patient  paralyzed  by  some  injury  of  the  spinal  cord  that 
has  left  the  lumbar  enlargement  intact,  has  his  foot  touched, 
the  leg  is  quickly  withdrawn;  not  only  without  a  cerebral 
act.  but  even  without  his  brain  being  in  any  way  affected, 


THE  FUNCTIONS  OP  THE  NERVOUS  SYSTEM.         57 

unless  indirectly  by  the  shaking  of  the  bed.  Thus  the 
branched  corpuscles  and  fibres  contained  at  that  point  in 
the  cord  with  which  the  afferent  and  efferent  nerves  of 
the  leg  are  connected,  have  at  once  the  function  of  giving 
out,  when  the  disturbance  is  communicated  to  them,  the 
requisite  quantity  of  molecular  motion,  and  of  so  directing 
this  to  the  respective  muscles  of  the  leg,  as  to  cause  the 
appropriate  movement.  More  involved  co-ordi- 

nations are  effected  by  the  co-operation  of  several  such 
centres,  or  portions  of  the  grey  substance,  contained  in 
adjacent  parts  of  the  spinal  cord.  In  the  human  subject 
demonstration  of  this  is  not  easy;  but  it  is  shown  by  ex- 
periments on  inferior  Yerteb^ata.  A  decapitated  frog  that 
has  its  side  irritated,  will  bring  the  hind  foot  of  that  side 
to  the  spot,  and  move  it  so  as  to  displace  the  irritating 
object.  Even  something  further  is  done.  If  a  scalpel  bo 
applied  to  the  skin  between  the  hind  legs,  these  act  jointly 
in  such  a  manner  as  to  push  away  the  scalpel.  The  explana- 
tion is  that  by  commissural  fibres,  transverse  and  longi- 
tudinal, the  disturbances  conveyed  to  particular  centres, 
are  communicated  to  sundry  adjacent  centres;  and 
through  their  efferent  nerves  these  direct  and  appor- 
tion the  multiplied  disturbances  among  a  great  variety 
of  muscles.  How  such  definite  co-ordinations 

as  these  are  effected  by  such  an  apparatus,  we  shall  better 
understand  on  remembering  that  the  relations  between 
positions  on  the  skin  and  the  movements  needed  to  bring 
the  extremities  to  touch  them,  are  tolerably  constant.  A 
frog's  hind  foot  can  reach  a  given  point  on  the  frog's  side, 
only  by  one  particular  muscular  adjustment;  or,  at  any  rate, 
by  a  muscular  adjustment  that  varies  within  narrow  limits. 
And  since  in  all  frogs,  generation  after  generation,  the  pro- 
portions of  parts,  and  therefore  the  relations  of  muscular 
adjustments  to  given  positions,  remain  practically  the  same ; 
it  becomes  comprehensible  how,  through  the  organized 
nervous  connections  that  arise,  a  touch  at  any  point  may 


58  THE  DATA  OF  PSYCHOLOGY. 

cause  the  combined  contractions  needful  to  bring  the  end 
of  the  limb  to  that  point.  It  should  be  observed 

here,  that  the  conception  of  these  acts  of  the  spinal  cord  as 
co-ordinations  of  motions,  is  incomplete  so  long  as  the  only 
motions  contemplated  are  those  of  the  muscles.  Under  the 
head  of  motions  must  be  included  the  disturbances  con- 
veyed along  the  afferent  nerves;  for  the  muscular  motions 
are  so  adjusted  that  their  joint  results  have  special  rela- 
tions to  these  received  disturbances.  The  co-ordination 
is  between  the  Teaijpio-motor  acts  and  the  dirigo-motor 
acts.  We  may,  then,  regard  the  spinal  cord  as  a 

centre  of  co-ordinations  which,  though  some  of  them  have 
considerable  complexity,  are  yet  relatively  simple — simple, 
inasmuch  as  the  disturbances  received  from  the  skin  are 
much  alike  from  all  parts;  simple,  inasmuch  as  each 
muscular  adjustment  is  mainly  of  a  fixed  or  invariable  kind; 
and  simple,  inasmuch  as  the  component  acts  of  the  co- 
ordinated group  are  practically  simultaneous. 

That  enlarged  and  differentiated  part  of  the  spinal  cord 
called  the  meduUa  oblongata^  including  the  root-portion  of 
the  pons  Va/roUi,  adnate  with  it  and  structurally  so 
entangled  that  the  two  cannot  be  demarcated,  we  may 
roughly  distinguish  as  a  centre  of  compound  co-ordination. 
It  receives  directly  the  auditory  impressions,  the  impressions 
of  taste,  and,  indirectly  through  the  corpora  quadrigemina,  is 
affected  by  visual  impressions :  meanwhile  sending  impulses 
to  the  various  muscles  of  the  eyes,  the  face,  the  jaws,  and 
the  mouth.  By  it  the  movements  of  all  four  limbs  are  com- 
bined in  joint  acts ;  and  by  simultaneously  regulating  them, 
it  makes  the  head  and  jaws  co-operate  with  the  limbs.  The 
various  impressions  and  muscular  motions  implied  by  the 
act  of  swallowing,  it  brings  into  due  relation.  Receiving 
the  respiratory  stimulus,  it  emits  the  stimuli  to  those 
muscles  which  enlarge  and  diminish  the  thoracic  cavity,  so 
causing  inspiration  and  expiration;  and,  as  a  consequence,  it 
is  the  centre  which,  disturbed  by  the  more  violent  irritations 


THE  FUNCTIONS   OP  THE  NERVOUS  SYSTEM.         69 

of  the  respiratory  surface,  sends  out  to  the  respiratory 
muscles  those  more  violent  impulses  which  cause  coughing 
and  sneezing :  to  which  may  be  added,  as  actions  belonging 
to  the  same  class,  crying  and  yawning.  Lastly,  through 
the  pneumogastric  nerve,  it  controls  the  action  of  the  heart, 
and  the  actions  of  other  viscera.  Thus  it  is  a  centre  to 
which  come,  in  some  cases  directly  but  in  most  cases  in- 
directly, impressions  from  all  parts  of  the  external  surface, 
as  well  as  from  the  mucous  lining  of  the  mouth, 
oesophagus,  and  lungs;  and  to  which  there  also  come, 
directly  or  indirectly,  impressions  received  through  the 
higher  senses.  At  the  same  time  the  minor  centres  severally 
commanding  groups  of  muscles,  are  by  it  put  in  relation 
with  one  another;  and  their  respective  simple  actions  so 
combined  as  to  constitute  compound  actions.  In  short  it 
has  recipio-motor  relations  with  all  the  parts  that  hold  con- 
verse with  the  external  world,  while  it  has  dirigo-motor 
relations  with  all  the  parts  that  react  on  the  external  world; 
and  its  function  is  that  of  adjusting  the  complex  movements 
in  obedience  to  the  complex  stimuli.  This  is  not  all.  Being 
the  centre  which  initiates  and  directs  involved  and  extensive 
bodily  actions,  entailing  rapid  expenditure,  it  is  the  centre 
in  which  the  demand  for  materials  is  indicated;  and  hence  it 
becomes  the  regulator  of  the  circulation,  of  the  aeration  of 
the  blood,  and  of  the  visceral  actions  generally.  Clearly,  then, 
its  co-ordinations  are  compound  in  comparison  with  those  of 
the  spinal  cord — compound,  because  the  impressions  which 
afferent  and  centripetal  nerves  bring  to  it,  are  not  only  more 
numerous  but  also  more  heterogeneous;  compound,  because 
the  impulses  which  it  sends  out  are  also  more  numerous  and 
more  heterogeneous;  and  compound,  because  it  brings  more 
involved  acts  into  correspondence  with  more  involved  stimuli. 
The  functions  of  the  two  still  higher  centres,  the  cere- 
hellum  and  the  cerebrum  have  now  to  be  defined  in  terms 
of  the  same  nature.  How  shall  we  express  them?  Both 
of  these  great  bi-lobed  masses  arise  as  buds  out  of  the 


60  THE  DATA  OP  PSYCHOLOGY. 

originally  almost-uniform  cranio-spinal  axis;  and  as  they 
enlarge,  their  distal  portions  grow  more  massive  than  their 
proximal  portions,  so  that  they  end  in  being  pedunculated. 
Each  of  them  thus  bears  to  the  medulla  oblongata^  a  relation 
like  that  which  the  superior  ganglion  H,in  the  diagrammatic 
Fig.  4,  bears  to  the  inferior  ganglion  F;  and  we  may  not 
unreasonably  infer  that  their  functions  are  analogous  to 
those  hypothetically  assigned  to  the  ganglion  H.  That  is  to 
say,  we  may  regard  them  as  organs  of  doubly-compound  co- 
ordination— organs  which  have  for  their  common  function, 
the  re-combining  into  larger  groups,  and  into  countless 
different  orders,  the  already-complex  impressions  received 
by  the  medulla  ohlongata  ^  and  which  have  the  further 
function  of  so  arranging  the  already-complex  motor  im- 
pulses issuing  from  the  medulla  oblongata,  as  to  form  those 
far  more  involved  aggregate  actions,  simultaneous  and 
successive,  which,  being  adjusted  to  these  involved  im- 
pressions, achieve  remote  ends.  The  general  truth  of  this 
definition  may,  I  think,  be  safely  assumed;  since  it  is 
simply  a  statement  in  other  terms,  of  what,  in  ordinary 
language,  is  called  intelligent  action;  which  habitually 
characterizes  vertebrate  animals  in  proportion  as  these 
centres  are  largely  developed.  Thus  much  being  granted, 
there  arises  the  further  question — what  are  the  respective 
parts  played  by  these  two  great  organs  in  this  doubly-com- 
pound co-ordination?  Much  difference  of  opinion  has  long 
existed,  and  still  exists,  respecting  the  particular  offices  of 
these  supreme  ganglia;  and  especially  respecting  the  office 
of  the  cerebellum.  Without  committing  myself  to  it  as 
anything  more  than  a  hypothesis,  I  will  here  venture  to 
suggest  a  not  improbable  interpretation.  The 

common  function  of  the  two  being  that  of  co-ordinating  in 
larger  groups  and  in  various  orders,  the  impressions  and 
acts  co-ordinated  in  the  lower  centres,  we  may  fitly  ask — 
are  there  any  fundamentally  distinct  kinds  of  order  in  which 
impressions  and  acts  may  be  co-ordinated  ?     The  obvious 


THE  FUNCTIONS  OF  THE  NERVOUS  SYSTEM.         61 

answer  is,  that  there  are  the  two  fundamentally  distinct 
orders  of  Co-existence  and  Sequence.  All  phenomena  are 
presented  to  us  either  as  existing  simultaneously  or  as 
existing  successively.  If,  then,  these  two  highest  nervous 
centres,  which  together  perform  the  general  function  of 
doubly-compound  co-ordination,  take  separate  parts  of  this 
function,  as,  from  their  separateness,  we  must  conclude  that 
they  do;  we  can  scarcely  make  a  more  reasonable  assump- 
tion than  that  the  respective  orders  in  which  they  co- 
ordinate compound  impressions  and  acts,  answer  to  the  re- 
spective orders  in  which  phenomena  are  conditioned.  In 
brief,  the  hypothesis  thus  reached  d  priori,  is  that  the 
cerebellum  is  an  organ  of  doubly-compound  co-ordination 
in  space  /  while  the  cerebrum  is  an  organ  of  doubly-com- 
pound co-ordination  in  timje.  The  d  posteriori 
evidence,  so  far  as  I  have  examined  it,  appears  congruous, 
both  with  this  view  of  the  general  function  of  these  centres, 
and  with  this  view  of  their  respective  special  functions. 
There  is  complete  harmony  between  the  hypothesis  and  the 
seemingly-strange  facts  that  these  centres  may  be  partially 
destroyed  without  causing  obvious  incapacity,  and  that 
they  may  be  wholly  removed  without  destroying  the  ability 
to  co-ordinate  the  less  complex  impressions  and  acts.  As- 
suming, as  we  may  fairly  do,  that  the  cells  and  fibres  which 
subserve  the  more  involved  co-ordinations,  are  successively 
added  at  the  surfaces  of  these  centres  as  they  develop,  it  is 
inferable  that  the  superficial  parts  may  be  sliced  off  with 
the  least-appreciable  effects  on  the  actions;  and  that  the 
effects  on  the  actions  will  become  conspicuous  in  proportion 
as  the  slices  destroy  the  parts  nearer  to  the  lower  centres: 
and  these  are  the  results  established  by  experiment.  Besides 
finding,  as  the  hypothesis  leads  us  to  expect,  that  these 
nervous  masses  are  relatively  large  in  all  creatures  capable 
of  adjusting  their  involved  and  continuous  actions  to 
complex  and  distant  environing  agencies;  we  also  trace 
some  relation  between  the  development  of  each  and  the 


62  THE  DATA  OP  PSYCHOLOGY. 

peculiar  capacities  of  the  species.  There  is,  for  instance, 
the  fact  that  the  cerebellimi  is  unusually  developed  in  birds 
of  prey,  which  have  to  co-ordinate  with  great  accuracy  the 
relations  of  distance,  direction,  and  complex  form,  as  well  as 
very  precisely  to  co-ordinate  the  involved  movements  ap- 
propriate to  these  involved  impressions.  And  there  is,  on 
the  other  hand,  the  fact  that  the  cerium  predominates  in 
creatures  showing,  like  ourselves,  the  power  of  adapting, 
throughout  long  periods,  concatenated  compound  actions  to 
concatenated  compound  impressions.* 

Of  course  this  classification  of  the  functions  of  the  nervous 
centres,  as  co-ordinations  that  are  simple,  compound,  and 
doubly  compound,  must  be  taken  as  merely  approximate. 
N^o  definite  divisions  can  be  made.  The  functions  arise 
through  increasing  complications;  and  these  general  con- 
trasts become  conspicuous  only  when  we  look  at  the 
facts  in  their  main  outlines.     Here,  however,  where  the 

*  Let  me  here  draw  attention  to  papers  in  the  Medical  Times  and  Qa- 
zette,  for  December  14  and  December  21,  1867,  in  which  Dr.  Hughlings 
Jackson  has  published  some  facts  and  inferences  that  quite  harmonize 
•with  these  interpretations,  in  so  far  as  the  common  function  of  the  great 
nervous  centres  is  concerned. 

It  should  be  remarked  that  the  above-proposed  definitions,  are,  to  a  con- 
siderable extent,  coincident  with  current  conceptions.  The  cerebrum  is 
generally  recognized  as  the  chief  organ  of  mind ;  and  mind,  in  its  ordinary 
acceptation,  means  more  especially  a  comparatively  intricate  co-ordination 
in  time— the  consciousness  of  a  creature  "  looking  before  and  after,"  and 
using  past  experiences  to  regulate  future  conduct.  In  like  manner  the  func- 
tion ascribed  to  the  cerebellum  in  the  foregoing  paragraph,  partially  agrees 
with  that  which  M.  Flourens  inferred  from  his  experiments.  It  differs,  how- 
ever, in  two  respects.  It  implies  that  the  cerebellum  is  not  an  organ  for  the 
co-ordination  of  motions  only,  or  of  synchronous  motions  only ;  but  that  it 
is  also  an  organ  for  the  co-ordination  of  simultaneous  impressions,  and  for 
the  co-ordination  of  the  synchronous  motions  in  adaptation  to  the  simultane- 
ous impressions.  And  it  further  implies  that  not  all  simultaneous  impres- 
sions and  adapted  synchronous  motions  are  co-ordinated  by  the  cerebellum  ; 
but  only  the  doubly-compound  ones,  which  have  for  their  external  correla- 
tives the  intricate  combinations  of  attributes  that  distinguish  objects  from 
one  another,  and  the  more  multiplied  and  varied  localizations  of  objects  in 
the  spacethatextends  beyond  theimmediate  limits  and  reach  of  the  organism. 


THE  FUNCTIONS  OF  THE  NERVOUS  SYSTEM.         63 

object  is  to  give  an  idea  of  the  principles  of  nervous  func- 
tion in  its  successive  stages  of  evolution,  detailed  qualifica- 
tions do  not  concern  us. 

§  23.  A  few  words  are  due  to  the  functions  of  that  sub- 
ordinate nervous  apparatus,  the  structure  of  which  we 
glanced  at  in  the  last  chapter — the  nervous  apparatus  pre- 
siding over  the  vital  processes.  It  will  suffice  if  we  take 
the  functions  of  the  vaso-motor  division  of  it  as  exemplifying 
the  whole. 

Each  vaso-motor  nerve,  having  roots  in  both  the  cerebro- 
spinal system  and  the  sympathetic  system,  conveys  to  all 
branches  of  the  artery  it  accompanies,  the  impulses  arising 
from  the  activities  of  the  great  nervous  centres  and  muscles, 
as  well  as  from  the  activities  of  the  viscera.  Probably  the 
ordinary  amount  of  disturbance  propagated  along  each  vaso- 
motor nerve,  simply  excites  the  muscular  coats  of  the  adja- 
cent artery  sufficiently  to  maintain  its  due  elasticity.  But 
stronger  disturbances  produce  marked  alterations  of  its 
calibre:  those  brought  by  the  sympathetic  fibres  being 
said  to  cause  contraction;  and  those  brought  by  fibres  from 
the  cerebro-spinal  system  being  said  to  cause  dilatation. 
Some  of  these  changes  have  relation  to  actions  going  on 
in  the  part  itself;  and  others  to  actions  going  on  in  the 
chief  vital  organs,  or  in  the  body  as  a  whole.  But  all 
of  them  show  us  that  by  means  of  the  vaso-motor  nervous 
system,  the  blood-vessels  are  so  regulated  as  to  subserve 
general  and  local  needs.  One  further  fact  belong- 

ing to  this  class  may  be  added;  partly  because  of  its  in- 
trinsic interest,  and  partly  because  it  illustrates  certain 
supplementary  nervous  functions  not  hitherto  named.  We 
have  already  seen  that,  among  its  many  duties,  the 
Tnedulla  oblongata  controls,  through  the  medium  of  the 
pneumogastric  nerve,  the  action  of  the  heart.  So  long 
as  the  disturbance  conveyed  to  the  meduUa  oblongata^  either 
from  the  periphery  of  the  nervous  system  or  from  its  great 


e4  THE  DATA  OP  PSYCHOLOGY. 

centres,  does  not  exceed  a  moderate  amount,  the  resulting 
waves  of  molecular  change  sent  by  it  through  the  pneumo- 
gastric,  do  not  interfere  with  the  heart's  action — perhaps  en- 
force it.  But  when  the  medulla  is  excessively  disturbed,  the 
increased  quantity  of  stimulus  it  sends,  either  diminishes  the 
action  of  the  heart,  or  stops  it  altogether :  so  causing  arrest 
of  the  circulation  and  consequent  insensibility.  Noting,  as 
we  pass,  that  this  is  one  of  the  most  remarkable  forms  of 
that  co-ordination  which  the  nervous  system  ever^^where 
effects,  since  the  arrangement  is  such  that  when  the  nervous 
system  becomes  abnormally  active,  and  its  chief  centres  sur- 
charged with  blood,  they  themselves  arrest  the  organ  which 
propels  blood  to  them;  we  have  to  ask  how  it  happens  that 
in  this  case  the  propagation  of  disturbance  through  a  nerve 
checks  action  instead  of  causing  it.  The  reply  is  that  in 
addition  to  the  systems  of  nerves  which  excite  action,  there 
is  found  to  exist  a  system  of  nerves  which  diminish  action — 
imMbitory  nerves  as  they  are  called.  Through  these  it  is 
alleged  that  the  brain  controls  the  spinal  cord — restraining 
those  reflex  movements  which,  when  connection  with  the 
brain  is  cut  off,  become  so  much  more  marked.  And  through 
one  of  these  it  is  concluded  that  the  medulZa  oblongata  reins 
in  the  heart,  when  the  cerebral  irritation  is  excessive. 

Be  this  as  it  may,  the  facts  named  illustrate  the  way  in 
which  the  nervous  system,  while  it  co-ordinates  the  external 
actions,  also  co-ordinates  those  internal  actions  which  make 
them  possible.  The  reader  has  but  to  conceive  that  through 
other  systems  of  nerves,  other  organs  which  absorb,  secrete, 
excrete,  &c.,  are  similarly  controlled,  and  he  will  under- 
stand sufficiently  for  present  purposes,  how  demand  for 
materials  and  supply  of  materials  are  harmonized. 

§  24.  In  summing  up  the  functions  of  the  nervous  system 
as  thus  formulated  in  terms  of  motion,  it  will  be  useful  to 
observe  the  greater  comprehensiveness  of  view  we  obtain 
by  excluding  the  ordinary  implications. 


THE  FUNCTIONS  OF  THE  NERVOUS  SYSTEM.         65 

When  one  part  of  a  Zoophyte  is  touched,  the  contraction 
set  up  in  that  part  slowly  diffuses  itself  through  the  whole 
body.  Two  things  are  here  to  be  noted.  There  is  a  propa- 
gation of  disturbance  through  the  nerveless  sarcode  of 
which  the  creature  is  composed;  for  distant  parts  are 
eventually  affected.  There  is  also  an  increase  of  disturb- 
ance; for  in  successive  moments  the  mass  of  tissue  under- 
going change  is  greater.  Thus  the  relatively-homogeneous 
substance  of  these  simple  animals,  exhibits  the  two  essential 
phenomena  exhibited  by  the  nervous  system  in  all  phases  of 
its  development:  there  is  propagation  of  molecular  motion, 
and  there  is  a  simultaneous  augmentation  of  this  mole- 
cular motion.  Such  essential  phenomena  grow  more  con- 
spicuous as  the  nervous  system  develops,  partly  because  the 
changes  set  up  become  limited  to  narrow  lines  and  small 
masses,  and  partly  because  the  matter  of  which  these  are 
formed  becomes  distinguished  by  an  increased  degree  of 
the  general  instability.  Since,  then,  the  functions  of  the 
nervous  system  as  expressed  in  terms  of  molecular  motion, 
are  functions  exhibited  in  a  vague  way  by  the  undifferenti- 
ated tissue  from  which  the  nervous  system  insensibly  arises; 
it  is  clear  that  by  so  expressing  them  we  include  alike  their 
lowest  and  their  highest  forms,  which  we  cannot  otherwise 
do. 

Moreover,  only  in  these  terms  can  there  be  given  an 
adequate  definition  of  fully-developed  nervous  functions. 
If  we  admit  any  subjective  element,  our  definition  becomes 
inapplicable  to  all  those  nervous  actions  which  have  no  sub- 
jective accompaniments — which  go  on  without  feelings; 
and  a  conception  of  nervous  functions  which  excludes  those 
of  organic  life,  cannot  be  a  complete  conception.  On  the 
other  hand,  the  definition  of  nervous  functions  as  consist- 
ing in  the  conveyance  and  multiplication  of  molecular 
motions,  holds  in  all  cases.  It  includes  equally  the  conduc- 
tion of  an  impression  made  on  a  nerve  of  sense,  and  the 
excitement  of  chemical  metamorphoses  in  a  gland. 


QQ  THE  DATA  OF  PSYCHOLOGY. 

The  subdivision  of  this  general  function  under  the  above- 
proposed  heads  of  recipio-motor^  libero-motor,  and  dirigo- 
motor^  has  also  the  advantage  of  greater  comprehensive- 
ness. No  word  at  present  in  use  expresses  the  office  which 
afferent  nerves  have  in  common,  more  specifically  than  the 
word  afferent  itself  expresses  it.  Whether  disturbance  of 
its  outer  end  produces  in  an  afferent  nerve  a  change  causing 
a  reflex  contraction,  or  whether  it  produces  a  change  causing 
what  we  call  a  sensation,  is  a  circumstance  of  secondary- 
import;  as  is  proved  by  the  fact  that  by  use  the  last  may 
become  the  first.  The  essential  thing  common  to  the  two, 
is  that  molecular  motion  is  propagated  from  periphery  to 
centre.  So,  too,  is  it  with  the  Ubero-motor  functions. 
Whether,  as  in  the  ganglia  of  the  sympathetic,  the  multipli- 
cation of  communicated  disturbance  has  no  subjective  con- 
comitant, or  whether,  as  in  the  cerebmm^  it  has  a  subjective 
concomitant,  there  is  in  both  cases  a  liberation  of  molecular 
motion;  and  this,  being  the  common  character  of  the 
changes  in  nerve-centres,  must  determine  the  definition  of 
their  common  function.  In  like  manner,  all  efferent  nerves, 
whether  conveying  disturbances  that  set  up  contractions  in 
muscles,  or  cause  constrictions  of  arteries,  or  excite  chemical 
transformations  in  glands,  serve  to  direct  the  waves  of 
molecular  motion — waves  that  are  intrinsically  alike  in 
nature,  though  the  results  produced  by  them  in  the  organs 
to  which  they  are  carried  differ  go  widely,  and  though  they 
are  now  associated  with  consciousness  and  now  are  not. 

A  more  special  view  of  the  functions  thus  classed,  dis- 
closes two  essential  facts.  Considered  as  an  agent  for 
generating  movements,  we  see  that  the  nervous  system 
acts  by  liberation  of  successively-larger  amounts  of  mole- 
cular motion  in  the  centres  successively  disturbed.  A  very 
small  change  at  the  outer  end  of  an  afferent  nerve,  sets  up  a 
relatively-large  quantity  of  change  in  some  adjacent  un- 
stable nerve-matter;  whence  the  change,  thus  increased,  is 
propagated  to  some  internal  ganglion;   to  be  passed  on  by 


THE  FUNCTIONS  OF  THE  NERVOUS  SYSTEM.         67 

it  immensely  multiplied  as  before;  until  there  is  unlocked 
an  amount  of  disturbance  capable  of  causing  muscular  con- 
tractions throughout  the  whole  body. 

Meanwhile  these  centres  in  which  molecular  motion  is 
liberated,  are  also  the  centres  in  which  it  is  co-ordinated; 
and  the  successively  higher  and  larger  centres  which  evolve 
successively  larger  quantities  of  molecular  motion,  are  also 
centres  in  which  successively  more  complex  co-ordinations 
are  effected.  Whence  follows  the  general  result  that  along 
with  each  further  development  of  the  nervous  system, 
enabling  it  to  make  all  parts  of  the  body  work  together 
more  efficiently  in  simultaneous  and  successive  actions, 
there  goes  an  increased  power  of  evolving  the  energy  re- 
quired for  such  larger  aggregates  of  actions. 

These  principles  we  found  to  be  well  exemplified  in  the 
case  which  most  nearly  concerns  us.  It  is  needless  to 
re-state  the  results  so  recently  arrived  at.  One  remark, 
however,  may  be  added.  In  the  functions  of  the  suc- 
cessively-higher vertebrate  centres,  reaching  their  climax 
in  the  human  being,  we  see  well  exemplified  the  law  of 
development  of  functions  in  general  {First  Principles, 
Part  II.  §  142).  This  progress  from  co-ordinations  that 
are  small  and  simple  to  those  that  are  larger  and  compound, 
and  to  those  that  are  still  larger  and  doubly  compound,  is 
one  of  the  best  instances  of  that  progressive  integration  of 
motions,  simultaneously  becoming  more  heterogeneous  and 
more  definite,  which  characterizes  Evolution  under  all  its 
forms. 


CHAPTEK  IV. 

THE    CONDITIONS    ESSENTIAL   TO    NERVOUS    ACTION. 

§  25.  Of  these,  the  first  in  order  is  continuity  of  nerve- 
substance.  Disturbance  is  not  conveyed  from  end  to  end  of 
a  nerve  that  has  been  cut  in  two;  and  section  of  a  nerve- 
centre  similarly  prevents  the  transfer  of  an  impulse  from  one 
of  the  dissevered  parts  to  the  other. 

The  requisite  continuity  is  not  simply  the  continuity  of 
unbroken  contact:  there  must  be  continuity  of  molecular 
cohesion.  Placing  in  apposition  the  two  ends  of  a  divided 
nerve,  does  not  re-establish  nervous  communication.  Even 
when,  after  a  cut,  the  surrounding  flesh  has  been  healed,  it 
is  long  before  the  sundered  nerve-threads  re-unite  so  com- 
pletely that  they  transmit  stimuli  as  well  as  before. 

Further,  there  must  be  no  destruction  of  continuity  by 
molecular  disorganization.  Without  division  of  a  nerve,  and 
without  injury  of  its  sheath,  there  may  result  from  disease  a 
change  which  incapacitates  the  nerve-fibres — an  atrophy,  or 
a  breaking-up  by  decomposition:  the  result  being  a  de- 
rangement of  those  lines  of  peculiar  nitrogenous  molecules 
which  receive  and  pass  on  the  waves  of  disturbance. 

§  26.  Nerve-structures,  whether  peripheral  or  central, 
permanently  disabled  as  they  are  by  actual  discontinuity, 
either  molar  or  molecular,  are  temporarily  disabled  by  dis- 
continuity of  molecular  equilibrium.    Pressure  is  capable  of 

68 


THE  CONDITIONS  ESSENTIAL  TO  NERVOUS  ACTION.     69 

producing  re-arrangement  of  particles,  even  in  substances 
that  are  simple  and  comparatively  hard;  as  is  shown  by  its 
power  of  altering  the  direction  of  diamagnetic  polarity  in 
metals.  We  may  therefore  expect  that  in  substances  of  com- 
plex composition  and  little  cohesion,  pressure  will  readily 
cause  the  particles  to  change  their  relative  positions.  Hence 
there  is  no  difficulty  in  understanding  why  nerve-substance, 
having  a  balanced  molecular  structure  such  that  it  is  ever 
ready  to  pass  when  disturbed  from  one  of  its  isomeric  states 
to  the  other,  may  be  so  modified  by  pressure,  even  when 
small,  as  to  be  incapacitated  for  undergoing  these  alternate 
molecular  re-arrangements.  Be  this  as  it  may,  however,  the 
fact  is  that  one  of  the  conditions  to  nervous  action  is  ab- 
sence of  much  pressure. 

In  the  case  of  nerve-trunks,  demonstration  of  this  general 
truth  is  easy.  A  ligature  round  a  nerve  prevents  a  dis- 
turbance set  up  at  one  end  of  it  from  producing  any  effect 
at  the  other  end.  Partial  results  of  this  nature  are  familiar. 
By  external  pressure  on  a  limb,  the  conducting  power  of  the 
nerves  affected  is  much  diminished. 

That  pressure  on  the  centrally-seated  tracts  of  fibres, 
hinders  or  arrests  their  actions,  is  shown  in  every  case  of 
paralysis.  By  a  clot  of  blood  that  has  escaped  from  a 
ruptured  vessel,  or  by  a  quantity  of  lymph  that  has  oozed 
through  the  walls  of  capillaries  over-distended,  bundles  of 
fibres  at  the  base  of  the  brain,  or  in  the  spinal  cord,  are  un- 
duly squeezed;  and  if  afferent  or  centripetal  fibres  they 
cease  to  bring  disturbances  from  the  periphery,  while  if 
efferent  or  centrifugal  fibres  they  cease  to  convey  impulses 
to  the  muscles. 

The  like  is  true  of  nerve-centres  as  wholes.  Indeed  pres- 
sure appears  to  be  a  greater  hindrance  to  their  actions  than 
to  the  actions  of  nerve-trunks.  That  certain  forms  of  the 
abnormal  arrest  of  nervous  action  called  coma,  are  due  to 
excessive  congestion  of  the  blood-vessels  of  the  encephalon, 
seems  possible;  but  as  some  question  this  interpretation  we 


70  THE  DATA  OP  PSYCHOLOGY. 

cannot  safely  base  an  inference  on  it.  There  is,  however,  one 
conclusive  piece  of  evidence.  A  fracture  of  the  skull  that 
causes  indentation  over  a  considerable  area,  and  leaves  the 
bone  intruding  on  the  space  previously  filled  by  the  brain, 
stops  the  functions  of  the  brain — disturbances  sent  to  it 
call  forth  no  appropriate  co-ordinated  motions,  and,  indeed, 
no  motions  at  all.  But  when,  by  means  of  a  trephine,  the 
depressed  portion  of  bone  is  cut  out,  the  brain,  relieved  from 
pressure,  at  once  resumes  its  duties. 

Further  support  is  yielded  by  what  may  be  regarded  as 
converse  evidence.  If  excess  of  pressure  arrests  nerve- 
action,  and  if  the  normal  amount  of  pressure  allows  the 
normal  amount  of  nerve-action;  then  it  is  inferable  that 
nerve-disturbances  will  pass  with  undue  facility  if  the  pres- 
sure is  deficient.  Now  as  the  brain  is  contained  in  an  al- 
most-closed chamber  which  cannot  collapse,  it  follows  that 
if  the  cerebral  blood-vessels  are  rapidly  drained,  the  masses 
of  nerve-fibres  amid  which  they  ramify,  being  subject  to  less 
pressure  than  usual,  will  allow  waves  of  molecular  change  to 
pass  with  unusual  facility;  and  ordinary  impressions  pro- 
pagated to  the  centres,  will  produce  extraordinary  motor 
impulses.  Hence  the  seemingly-anomalous  fact  that  great 
loss  of  blood,  or  great  local  anaemia  caused  by  stoppage 
of  a  cerebral  artery,  causes  convulsions.  Such  a  result 
may  be  anticipated  as  the  first  result,  before  innutri- 
tion begins  to  tell;  though  innutrition  will  afterwards 
cause  prostration  or  paralysis.  And  this  is  the  order  in 
which  the  phenomena  actually  occur.  The  like 

appears  true  of  the  peripheral  nervous  system.  The  afferent 
nerves  of  individuals  who,  though  otherwise  healthy,  have 
lax  tissues,  are  often  unduly  impressible.  And  there  are 
instances  of  undue  local  impressibility  which,  I  think,  admit 
of  this  interpretation.  It  has  been  found  that  an  arm 
rendered  anaemic  by  unnatural  constriction  of  its  arteries, 
thereby  reduced  in  temperature  and  beginning  to  atrophy, 
may  nevertheless  have  its  afferent  nerves  affected  by  electric 


THE  CONDITIONS  ESSENTIAL  TO  NERVOUS  ACTION.     71 

discharges  in  an  unusual  degree.*  Deficient  pressure  on 
the  nerve-trunks  appears  a  possible  cause  of  this  otherwise 
strange  result. 

§  27.  Proof  that  heat  kept  above  a  certain  level  is  a  con- 
dition to  the  maintenance  of  nervous  action,  is  difl&cult  to 
disentangle  from  proof  that  the  maintenance  of  nervous 
action  depends  on  a  due  circulation  of  blood;  for  the  one 
condition  is  usually  but  a  concomitant  of  the  other.  Never- 
theless, there  is  reason  to  infer  that  a  supply  of  free  mole- 
cular motion  is  requisite,  apart  from  a  supply  of  nutritive 
materials. 

The  general  fact  that  cold-blooded  animals  are  com- 
paratively inactive,  admits  of  the  interpretation  that  their 
low  temperature  is  due  to  their  inactivity,  as  well  as  of  the 
interpretation  that  their  inactivity  is  a  consequence  of  their 
low  temperature;  for  the  two  act  and  react  in  such  a  way 
that  neither  can  properly  be  called  the  cause  of  the  other. 
But  reptiles  which  remain  quiescent  in  cold  weather,  and 
become  active  when  they  are  warmed  by  the  summer's  sun, 
yield  us  good  evidence.  Though  it  may  be  alleged  that 
their  greater  activity  arises  from  accelerated  circulation  and 
aeration  of  the  blood,  yet  as  the  heart  and  lungs  are  set 
going  by  their  respective  nervous  centres,  we  must  infer 
that  the  warming  of  these  nervous  centres  by  external  heat, 
is  the  initial  change  in  these  animals  that  have  but  little 
power  of  producing  heat  by  their  own  actions.  In 

support  of  this  interpretation  may  be  cited  the  converse 
fact.  When  active  creatures,  capable  under  ordinary 
conditions  of  generating  enough  heat  within  themselves, 
are  exposed  to  conditions  under  which  they  lose  heat  faster 
than  they  make  it,  their  nervous  actions  decrease,  and  they 
eventually  cease  to  move.    In  hybernating  mammals  we  see 

*  I  am  indebted  tor  this  fact  to  Dr.  Bastian,  who  observed  it  in  one  of 
his  own  patients. 


72  THE  DATA  OF  PSYCHOLOGY. 

an  annual  recurrence  of  this  relation  of  cause  and  effect; 
and  in  mammals  that  do  not  hybernate,  as  in  ourselves,  it 
equally  holds  that  prolonged  exposure  to  extreme  cold  de- 
presses nervous  action,  causing  strong  tendency  to  sleep, 
and  that  death  results  if  the  bodily  temperature  is  allowed 
to  fall  still  lower. 

That  local  loss  of  heat  when  carried  far,  is  followed  by 
local  inaction  of  the  nerves,  is  shown  by  the  fact  that  parts 
of  the  body  that  have  been  greatly  cooled  down,  naturally 
or  artificially,  may  be  pricked  or  cut  or  pinched  without  any 
of  the  usual  disturbances  being  conveyed  to  the  nerve- 
centres.  It  is  true  that  where  the  refrigeration  is  extreme, 
there  is  usually  a  partial  deprivation  of  blood;  but  there 
is  evidence  that  when  this  is  not  the  case — when,  indeed, 
the  blood-vessels  are  congested,  as  in  red  hands  on  a  winter's 
day,  loss  of  heat  entails  decrease  of  nerve-function.  That 
the  like  holds  of  the  respective  centres,  is  shown  by  the  use 
of  cold  as  a  therapeutic  agent:  ice  to  the  head  being  pre- 
scribed when  there  is  excessive  cerebral  action,  and  ice  to 
the  spine  being  a  means  of  diminishing  reflex  excitability. 

It  is  worth  remarking  that  this  dependence  of  nervous 
action  on  supply  of  heat,  yields  indirect  support  to  the  views 
set  forth  in  foregoing  chapters.  If,  as  was  inferred,  the 
disturbance  conveyed  along  a  nerve-thread  is  an  isomeric 
change,  during  which  some  molecular  motion  is  yielded  up 
by  each  molecule  as  it  passes  on  the  accumulated  wave  to 
its  neighbour — if  resumption  of  the  previous  isomeric  state 
implies  an  equivalent  absorption  of  molecular  motion  from 
surrounding  matter;  then,  in  proportion  to  the  heat  of 
surrounding  matter,  will  be  the  rapidity  with  which  the 
nerve-fibre,  resuming  this  previous  isomeric  state,  becomes 
fit  to  transmit  another  wave  of  molecular  change. 

§  28.  That  nerves  and  nerve-centres  act  only  so  long  as 
they  are  furnished  with  those  materials  which  the  blood- 
vessels bring  them,  is  a  familiar  truth.     The  quantity  of 


THE  CONDITIONS  ESSENTIAL  TO  NERVOUS  ACTION.     73 

blood  present  in  any  part,  and  the  rapidity  with  which  fresh 
blood  is  propelled  to  the  part,  both  aifect  the  degree  of 
nervous  activity  in  the  part. 

General  depletion  is  a  cause  of  nervous  inaction:  if  the 
total  quantity  of  blood  in  the  body  is  much  diminished,  the 
great  nervous  centres  are  the  first  organs  to  feel  the  change. 
Temporary  loss  of  blood  produces  fainting,  or  sudden  arrest 
of  cerebral  action;  and  permanent  deficiency  of  blood  is 
accompanied  by  debility,  which  implies  a  decreased  nervous 
discharge.  Supposing  that  no  blood  has  been  lost,  in- 
sensibility nevertheless  instantly  results  if  the  heart  ceases 
to  supply  the  brain  with  fresh  blood  in  place  of  the  blood 
it  contains.  Or  if  there  is  chronic  feebleness  of  the  heart's 
action,  there  is  proportionate  diminution  of  nervous  power. 
Where  the  total  quantity  of  blood  is  adequate  and  the  heart 
is  not  in  fault,  local  nervous  function  may  still  be  hindered 
by  local  anaemia,  resulting  from  aneurism  in  an  artery,  or 
from  what  is  called  an  embolism — a  plugging  up  of  an 
artery  with  coagulated  blood.  Thus  paralysis  is  caused  by 
embolism  of  the  cerebral  blood-vessel  which  supplies  the 
highest  part  of  the  motor  tract.  The  converse 

facts  similarly  imply  this  same  general  relation.  When, 
other  conditions  being  normal,  a  nerve-centre  is  highly 
charged  with  arterial  blood,  it  responds  with  unusual 
rapidity  to  the  disturbances  it  receives;  and  evolves  more 
than  ordinary  amounts  of  force,  shown  in  secondary  nervous 
changes,  or  in  muscular  motions,  or  both.  Supposing, 
again,  that  there  is  no  hypersemia  of  a  nervous  centre,  it 
will  still  happen  that  if  the  heart  propels  blood  to  it  with 
unusual  rapidity,  its  libero-motor  function  will  be  exalted. 

At  the  periphery  of  the  nervous  system,  like  variations  of 
efficiency  follow  like  variations  of  circulation.  A  reduction 
in  the  quantity  of  blood  present,  caused  by  constriction  of 
the  vessels,  is  probably  one  cause  of  the  decreased  nervous 
impressibility  in  a  part  that  is  exposed  to  cold;  and  to  the 
same  cause  is  perhaps  to  be  ascribed  some  of  the  comparative 


74  THE  DATA  OP  PSYCHOLOGY. 

sluggishness  with  which  the  muscles  of  the  part  respond  to 
motor  impulses.  If  instead  of  local  lack  of  blood  there  is 
retardation  or  stoppage  of  the  local  current  of  blood,  the 
nerves  of  the  part  similarly  become  incapacitated  in  a  pro- 
portionate degree:  instance  the  blindness  that  results  from 
blocking  up  the  central  retinal  artery;  or  instance  the  grad- 
ual disappearance  of  impressibility  in  a  region  of  the  skin 
that  has  had  its  supplying  blood-vessel  tied.  Con- 

versely, excess  of  blood  around  the  peripheral  nerve-fibres, 
causes  unusual  excitability  of  them.  A  gentle  touch  on  the 
skin  in  its  normal  state,  sends  through  the  afferent  nerves  a 
disturbance  so  small  as  to  call  forth  from  the  central  organs 
scarcely  any  response ;  but  where  the  skin  is  highly  inflamed, 
a  like  touch  affects  them  so  much  that  the  disturbance,  when 
reflected  from  the  central  organs,  produces  a  start  of  the 
whole  body.  If  in  addition  to  local  excess  in  the  quantity 
of  blood  there  is  an  accelerated  flow  of  blood,  a  still  greater 
exaltation  of  local  nervous  action  follows.  It  is  a  familiar 
truth  that,  other  things  remaining  the  same,  an  inflamed 
part  is  made  more  irritable  by  anything  which  increases  the 
action  of  the  heart. 

§  29.  Nervous  action  depends  not  alone  on  the  quantity 
of  blood  supplied  but  also  on  its  quality — on  the  proportion 
of  the  needful  elements  contained  by  it. 

General  rather  than  special  warrant  must  suffice  for  this 
proposition.  Little  is  known  about  variations  in  the  consti- 
tution of  the  blood ;  and  still  less  about  the  relations  between 
these  and  variations  of  nervous  activity.  That  a  blood 
greatly  impoverished,  as  in  dropsical  persons  (whose  tissues 
become  infiltrated  because  the  thin  serum  passes  too  easily 
through  the  walls  of  the  capillaries),  is  accompanied  by  ener- 
vation, is  pretty  clear;  and  we  can  scarcely  be  wrong  in 
concluding  that  a  blood  rich  in  the  constituents  of  nerve- 
substance,  renders  possible  a  great  evolution  of  nerve-force. 

But  there  is  indirect  evidence  serving  to  enforce  the  scanty 


THE  CONDITIONS  ESSENTIAL  TO  NERVOUS  ACTION.     76 

direct  evidence.  Tor  we  have  abundant  proof  that  by  add- 
ing certain  matters  to  the  blood,  unusual  amounts  of  nervous 
action  may  be  evoked.  Alcohol,  nitrous  oxide,  the  vegeto- 
alkalies,  and  other  stimulants,  are  not,  indeed,  components 
of  nerve-substance ;  nor  is  there  any  reason  to  suppose  that 
they  can  serve  in  place  of  components.  Probably  their  im- 
mediate influence  is  that  of  setting  up  or  facilitating  the 
change  of  nerve-substance,  and  so  causing  unusual  disen- 
gagement of  molecular  motion.  But  by  showing  that  the 
supply  of  particular  substances  to  the  nervous  system  exalts 
nervous  activity,  they  make  it  more  manifest  that  nervous 
activity  must  partly  depend  on  the  supply  of  substances 
which  re-build  nerve-tissue  as  fast  as  action  disintegrates  it. 
We  must  not  omit  a  further  qualitative  character  of  a 
positive  kind.  The  blood  must  contain  oxygen.  "What  is 
the  special  action  of  oxygen — whether  it  is  a  direct  disinte- 
grant  of  the  tissues,  including  nerve-tissue;  or  whether  it 
simply  facilitates  by  its  presence  molecular  disintegrations 
otherwise  caused;  or  whether  it  serves  merely  to  combine 
with,  and  carry  away,  the  products  of  such  disintegrations 
otherwise  caused;  are  questions  about  which  there  are 
differences  of  opinion.  But  there  can  be  no  difference  of 
opinion  as  to  the  necessity  for  an  oxygenated  blood.  And 
opinions  can  scarcely  differ  respecting  the  general  relation 
that  exists  between  the  degree  of  oxygenation  and  the  de- 
gree of  nervous  activity. 

§  30.  While,  for  the  maintenance  of  nervous  action,  it  is 
requisite  that  certain  matters  shall  be  present  in  the  blood,  it 
is  also  requisite  that  certain  other  matters  shall  be  absent; 
or,  to  speak  strictly,  that  they  shall  be  present  in  but  small 
proportions.  These  are  the  compounds  resulting  from  de- 
composition of  the  tissues — the  nervous  tissue  included.  The 
two  most  important  are  carbonic  acid  and  urea. 

If  the  exhalation  of  carbonic  acid  by  the  lungs  is  greatly 
retarded,  lethargy  ensues:    disturbances  at  the  periphery 


76  THE  DATA  OF  PSYCHOLOGY. 

of  the  nervous  system  fail  to  call  forth  the  usual  responses. 
If  the  exhalation  is  completely  arrested,  complete  insensi- 
bility is  soon  produced;  followed  quickly  by  arrest  of  the 
inferior  nervous  functions,  and  consequently  of  all  other 
functions.  And  these  effects  arise  still  more  rapidly  if  there 
is  an  absorption  of  carbonic  acid  through  the  lungs,  instead 
of  an  arrested  excretion  of  the  carbonic  acid  internally 
generated. 

In  an  analogous  but  less  rapid  manner,  a  decrease  and 
final  stoppage  of  nervous  action  is  caused  by  an  accumula- 
tion in  the  blood  of  urea,  or  of  those  nitrogenous  products 
represented  by  it.  If  the  kidneys  fail  to  perform  their  func- 
tion, or  if  the  waste  nitrogenous  products  which  they  have 
separated  from  the  blood  are  prevented  from  escaping  out  of 
the  body,  and  are  re-absorbed;  there  results  a  nervous  in- 
action, ending  presently  in  coma  and  finally  in  death. 

§  31.  Such,  stated  as  fully  as  is  needful  here,  are  the  con- 
ditions essential  to  nervous  action.  Qualifications  have  been 
passed  over;  and  much  evidence  has  been  omitted.  In 
summing  up  these  leading  facts  which  alone  concern  the 
psychologist,  we  may  with  advantage  observe  how  they 
harmonize  with  the  general  views  of  nerve-structure  and 
nerve-function  set  forth  in  foregoing  chapters.  All  these 
pre-requisites  to  nervous  action  obviously  admit  of  being 
grouped  as  pre-requisites  to  the  genesis  of  molecular 
motion,  and  pre-requisites  to  the  conveyance  of  molecular 
motion. 

That  molecular  motion  may  be  disengaged  there  must  be 
decomposition ;  and,  therefore,  for  the  discharge  of  molecular 
motion  to  be  maintained,  decomposition  must  be  facilitated. 
The  quantity  of  waste  being  a  measure  of  the  quantity  of 
force  evolved,  it  follows  that  the  nervous  system  requires 
a  good  supply,  and  quick  exchange,  of  blood;  since  in  the 
blood  are  brought  the  matters  that  favour  disintegration. 
Similarly   with   respiration,   considered   as   a   process   of 


THE  CONDITIONS  ESSENTIAL  TO  NERVOUS  ACTION.     77 

absorbing  that  oxygen  whicli  directly  or  indirectly  aids 
the  metamorphosis.  And  so  likewise  with  the  excre- 
tion of  those  waste  products  which  hinder  the  metamor- 
phosis. But  perpetual  waste  must  be  met  by 
perpetual  repair.  If  its  action  is  to  continue,  nervous  tissue 
must  be  re-composed  as  fast  as  it  is  decomposed.  Hence 
the  reason  why  there  is  needed  a  blood  that  is  rich  in  nerve- 
constituents.  Hence  the  fact  that  abundant  blood  must  be 
present  wherever  there  is  much  nervous  action.  And  hence, 
also,  the  necessity  for  an  efficient  circulation  to  replace  by 
fresh  blood,  the  blood  that  has  been  used. 

Equally  well  do  the  several  conditions  essential  to  the 
transmission  of  nervous  disturbance,  conform  to  the  hypo- 
thesis that  the  disturbance  transmitted  is  a  wave  of  isomeric 
change.  For  if  it  is,  we  at  once  see  why  there  must  be 
not  merely  contact-continuity  of  nerve-fibre,  but  molecular 
continuity.  We  are  helped  to  understand  how  pressure,  by 
deranging  that  delicate  molecular  balance  which  makes 
possible  the  alternation  of  isomeric  states,  may  prevent 
the  passage  of  nervous  discharges.  And  we  are  supplied 
with  an  explanation  of  the  fact  that  the  presence  of  free 
molecular  motion  or  heat,  is  needful  to  enable  a  nerve  con- 
tinually to  resume  its  fitness  for  conveying  a  wave  of  change. 

Before  closing  the  chapter  it  should  be  pointed  out  that 
these  many  conditions  essential  to  nervous  action,  are  never 
all  fulfilled  at  one  time  in  the  same  degree,  but  are  usually 
fulfilled  in  various  degrees  and  combinations;  and  that  by 
now  conspiring  and  now  conflicting,  they  produce  results 
that  are  complicated  and  often  perplexing.  Thus,  for  in- 
stance, substances  which  directly  stimulate  the  nervous 
system,  are  usually  substances  which  retard  the  exchange 
of  gases  in  the  lungs,  and  by  so  doing  depress  the  state 
of  the  nervous  system;  and  these  conflicting  actions,  diffe- 
rent in  their  proportions  in  different  individuals,  and  in  the 
same  individual  at  different  times,  often  work  opposite 
effects,  or  work  first  one  effect  and  then  the  other.    Again, 


78  THE  DATA  OF  PSYCHOLOGY. 

richness  of  blood,  by  facilitating  high  nutrition  of  nerve- 
centres,  conduces  to  nervous  activity.  Yet  there  is  a 
plethoric  state  which  is  not  nervously  active;  and  starva- 
tion, with  its  greatly  impoverished  blood,  has  a  phase  at 
which  delirium  sets  in,  in  consequence  of  the  unduly  rapid 
disintegration  of  the  nerve-centres.  Analogous  incongrui- 
ties, too  numerous  to  specify  here,  continually  occur.  This 
entanglement  of  the  conditions  must  be  borne  in  mind  and 
allowed  for  in  each  case. 


CHAPTEK  V. 

NEEVOUS  STIMULATION  AND  NEKVOUS  DISCHAEGE. 

§  32.  Every  agent  capable  of  altering  the  molecular  state 
of  a  nerve,  causes  the  nerve  to  produce  the  particular  change 
which  it  habitually  produces.  Experiments  prove  that  each 
nerve  is  made  to  work  the  same  kind  of  effect  by  stimuli  of 
all  orders;  or,  to  speak  strictly,  it  is  found  that  the  effect  is 
of  the  same  kind  wherever  its  kind  renders  it  accessible  to 
observation. 

Thus,  if  an  exposed  end  of  a  nerve  which  goes  to  a 
muscle  is  roughly  touched,  the  muscle  contracts.  If  it  is 
eroded  by  an  alkali  or  an  acid,  the  muscle  contracts.  If  it 
is  galvanized,  the  muscle  contracts.  If  it  is  suddenly  heated, 
still  the  muscle  contracts.  Similarly  with  a  vaso-motor 
nerve,  ^o  matter  whether  the  disturbing  agent  be  me- 
chanical, chemical,  thermal,  or  electric,  there  results  at  the 
peripheral  extremity  a  like  change  in  the  state  of  the  ad- 
jacent arteries. 

An  allied  truth  is  that  whether  a  nerve  be  irritated  at  the 
end  which  normally  receives  the  disturbance,  or  whether  it 
be  irritated  at  some  place  between  this  and  the  organ  acted 
upon  by  it,  the  effects  wrought  are  alike — in  nature,  at 
least,  if  not  in  degree.  As  already  said,  the  qucmtity  of 
change  set  up  increases  with  the  length  of  the  nerve  through 
which  the  impulse  is  transmitted.    But  the  quality  of  this 


80  THE  DATA  OF  PSYCHOLOGY. 

change  remains  identical  be  the  stimulus  applied  at  a  near 
point  or  a  remote  point. 

This  last  truth,  equally  with  the  first,  harmonizes  with  the 
supposition  on  which  we  have  thus  far  proceeded.  If  the 
disturbance  that  travels  along  a  nerve  is  a  wave  of  isomeric 
transformation,  the  kind  of  effect  produced  by  the  wave  at 
the  place  it  eventually  reaches,  will  be  the  same  whatever 
stimulus  set  it  up,  or  wherever  it  commenced. 

§  33.  Nerve  is  not  capable  of  continuous  stimulation  or 
continuous  discharge.  Persistent  action  of  whatever  kind 
on  a  nerve-termination  or  the  cut  end  of  a  nerve,  does  not 
produce  a  persistent  effect  on  the  connected  nerve-centre,  or 
on  the  connected  peripheral  organ. 

Supposing  the  nerve  supplying  some  muscle  has  been  dis- 
sected out  and  cut  in  two;  then,  if  the  exposed  part  be  sud- 
denly pressed  the  muscle  will  suddenly  contract;  but  main- 
tenance of  the  pressure  will  not  cause  maintenance  of  the 
contraction.  Or  if  this  nerve  is  made  part  of  an  electric 
circuit,  then,  at  the  moment  of  completing  the  circuit,  the 
muscle  will  contract;  but  its  contraction  is  only  momentary, 
and  the  subsequent  continuance  of  the  current  works  no 
visible  effect.  To  keep  up  muscular  contraction,  it  is  requi- 
site to  send  through  the  nerve  a  quick  succession  of  separate 
disturbances.  If  the  nerve  forms  part  of  an  electric  circuit 
in  which  there  is  an  apparatus  for  breaking  and  completing 
the  circuit;  then,  at  each  completion  of  the  circuit,  the 
muscle  contracts;  and  when  the  alternate  breaks  and  com- 
pletions follow  one  another  very  rapidly,  the  contraction  of 
the  muscle  becomes  practically  persistent.  This  truth  is 
demonstrable  by  experiment  on  a  dead  frog,  and  also  by 
experiment  on  the  living  human  subject.  A  man  who 
grasps  the  two  metallic  cylinders  forming  the  poles  of  a 
magneto-electric  machine,  cannot  leave  hold  of  the  cylinders 
when  the  intermittent  current  is  passed  through  his  arms. 
The  like  result  occurs  when  the  disturbances  are  mechanical 


NERVOUS  STIMULATION  AND  NERVOUS  DISCHARGE.     81 

instead  of  electric.  If  the  cut  end  of  a  motor  nerve  is  sub- 
ject to  a  rapid  series  of  taps,  the  muscle  it  supplies  is  thrown 
into  a  state  of  tetanus. 

The  fact  that  the  so-called  nerve-current  consists  of 
successive  pulses,  is  one  of  great  significance.  We  shall 
find  hereafter  that  it  has  many  important  corollaries.  For 
the  present  it  will  suffice  to  observe  how  entirely  congruous 
it  is  with  the  hypothesis  on  which  we  have  thus  far  pro- 
ceeded. If  a  nervous  disturbance  travels  as  a  wave  of  mole- 
cular change — if  this  wave  is  such  that  the  molecules  of 
nerve-substance  fall  from  one  of  their  isomeric  states  to  the 
other;  then,  having  fallen  in  passing  on  and  increasing  the 
pulse  or  shock,  they  remain  incapable  if  doing  anything 
more, until  they  have  resumed  their  previous  isomeric  state. 
Hence  the  very  nature  of  the  process  necessitates  the  inter- 
mittent character  of  nerve-action. 

§  34.  The  transmission  of  a  disturbance  through  a  nerve 
takes  an  appreciable  time.  The  rate  of  transmission,  as 
measured  by  Professor  Helmholtz,  has  been  found  to  vary 
from  about  28  yards  per  second  to  32  yards  per  second. 
Difference  of  constitution  is  doubtless  the  cause  of  this 
variation — a  variation  to  which  is  due  that  individual  pecu- 
liarity recognized  by  astronomers  in  what  they  call  "  the 
personal  equation." 

This  peculiarity  affords  yet  another  confirmation  of  the 
belief  that  a  nervous  discharge  is  a  wave  of  isomeric  trans- 
formation. If  the  disturbance  propagated  through  any 
series  of  molecules  is  one  that  does  not  permanently  change 
their  relative  positions ;  then  the  transfer  of  the  disturbance 
may  be  excessively  rapid,  because  the  amount  of  molecular 
momentum  to  be  generated  is  excessively  minute.  But  if  the 
molecules  have  to  be  transposed — if,  as  in  isomeric  transfor- 
mation, the  components  of  each  compound  molecule  have 
their  relative  positions  altered;  then  the  quantity  of  molecu- 
lar momentum  generated  must  be  comparatively  very  large; 


83  THE  DATA  OP  PSYCHOLOGY. 

and  as  the  genesis  of  this  momentum  takes  place  in  each 
molecule  before  the  next  is  affected,  the  transfer  of  the 
disturbance  must  be  greatly  retarded.* 

*  Perhaps  too  much  has  already  been  said  respecting  the  nature  of 
nerve-action.  But  before  finally  leaving  the  subject,  I  must  add  some 
important  illustrative  facts  that  have  come  to  my  knowledge  while  writ- 
ing this  chapter.  They  are  contained  in  a  paper  by  Mr.  Gore,  published 
in  the  Transactions  of  the  Royal  Society  for  1858,  describing  the  allotropic 
changes  undergone  by  electro-deposited  antimony.  Antimony  so  depos- 
ited assumes,  according  to  the  conditions,  two  forms — a  dark,  amorphous, 
or  unstable  form ;  and  a  grey,  crystalline,  or  stable  form.  When  a  mass 
of  the  amorphous  antimony  is  disturbed  at  one  end,  there  begins  a  change 
into  the  crystalline  antimony,  which  spreads  almost  instantly  throughout 
the  whole  mass,  with  great  evolution  of  heat.  A  slight  tap  with  a  hard 
substance  suffices  to  initiate  this  transformation.  Touching  one  of  the 
angles  with  a  hot  body  equally  produces  the  effect.  And  it  is  also  pro- 
duced by  an  electric  spark.  A  temperature  below  that  of  boiling  water 
sufficed  to  cause  the  change ;  and  Mr.  Gore  found  that  in  proportion  as 
the  whole  mass  was  raised  towards  this  temperature,  the  metamorphosis, 
more  easily  set  up,  travelled  with  greater  rapidity.  When  a  copper  wire 
was  coated  with  a  film  of  this  amorphous  antimony,  the  allotropic  change 
progressed  along  it  at  a  rate  varying  from  12  to  30  feet  in  a  minute. 
Absorption  of  the  evolved  heat  by  the  copper  wire,  was  found  to  be  the 
cause  of  retardation  when  the  change  advanced  slowly;  whence  it  fol- 
lows that  were  none  of  the  disengaged  heat  allowed  to  escape,  the  wave 
of  change  would  travel  much  faster,  A  further  significant  fact  is  that 
when  this  transformation  was  propagated  through  some  amorphous  an- 
timony that  had  been  previously  reduced  to  powder,  part  of  it  was  oxi- 
dized— the  disturbance  caused  by  the  allotropic  change  initiated  chemical 
change,  in  parts  of  the  substance  that  were  favourably  circumstanced  for 
chemical  change.  See  then  the  parallelism.  We  have  the  transformation 
set  up  indifferently,  as  in  nerve,  by  mechanical  force,  heat,  electricity. 
We  have  it  facilitated,  as  in  nerve,  by  raised  temperature.  We  have  it 
travelling  from  end  to  end  of  a  mass  with  a  velocity  which,  though  far  less 
than  that  of  the  nerve- wave,  is  still  considerable.  And  we  have  allotropic 
change  initiating  chemical  change,  just  as  we  concluded  that  isomeric 
change  in  a  nerve-fibre  sets  up  chemical  change  in  a  nerve-vesicle.  Let 
me  not  omit  an  interpretation  of  nerve-structure,  which  is  suggested  by 
Mr.  Gore's  experience  that  the  transmission  of  the  allotropic  change  is 
rapid  in  proportion  as  the  evolved  heat  is  retained.  In  developed  animals, 
nerve-fibres  are  surrounded  by  sheaths  of  medullary  matter ;  and  we  saw 
reasons  for  concluding  that  this  medullary  matter  is  an  insulator.  Now 
it  has  recently  been  discovered  that  white  or  fibrous  nerve-tissue,  is 
chemically  distinguished  from  grey  or  vesicular  nerve-tissue,  by  the 


NERVOUS  STIMULATION  AND  NERVOUS  DISCHARGE.      83 

§  35.  Allied  with  the  fact  that  a  nerve-disturbance  takes 
an  appreciable  time  to  travel  from  periphery  to  centre  or 
from  centre  to  periphery,  is  the  fact  that  the  effect  produced 

presence  in  large  quantity  of  a  substance  called  protagon  ;  and  this  sub- 
stance proves  to  be  of  excessively  complex  composition — has  a  molecule 
more  highly  compounded  than  any  other  known  molecule.  But  in  pro- 
portion as  molecules  become  complex  and  large,  the  masses  formed  of 
them  become  bad  conductors  of  molecular  motion.  It  is  inferable,  then, 
that  the  essential  nerve-fibre  is  imbedded  in  a  substance  especially  distin- 
guished by  inability  to  absorb  the  molecular  motion  disengaged  during 
the  isomeric  change  of  the  nerve-fibre. 

I  have  hitherto  passed  over  without  remark,  the  hypothesis  at  one  time 
current,  and  still  surviving  in  some  minds,  that  the  nervous  force  is 
either  electricity  or  some  form  of  force  allied  to  it.  In  addition  to  the 
many  foregoing  reasons  for  adopting  another  hypothesis,  it  may  be  well 
to  set  down  here  the  reasons  for  rejecting  this.  The  highest  rate  of  the 
nervous  discharge  is  some  32  yards  per  second.  The  electric  discharge 
travels  at  the  rate  of  280,000  miles  per  second.  The  one  velocity  is 
thus  nearly  16,000,000  times  the  other.  That  a  force  allied  to  the  electric 
should  have  a  velocity  so  enormously  different,  seems  very  unlikely. 
Again,  an  electric  current,  so  long  as  its  source  is  unexhausted  and  the 
circuit  unbroken,  is  a  continuous  ciirrent ;  but  the  nerve-current  is  not 
continuous.  Hence  if  the  nerve-force  is  of  a  kind  allied  to  the  electric, 
its  mode  of  alliance  is  quite  exceptional;  for  the  other  allied  forces, 
heat,  light,  and  magnetism,  are  not  intermittent.  Once  more,  nervous 
transmission  is  facilitated  by  heat ;  whereas  heat  is  an  obstacle  to  electric 
transmission,  and  diminishes  or  destroys  magnetic  action.  The  fact  is 
that  but  for  the  accidental  observation  of  Galvani,  the  suspicion  that  the 
nerve-force  is  electric  or  quasi-electric,  would  probably  never  have  been 
entertained ;  and  it  should  have  been  abandoned  as  soon  as  it  was  found 
that  other  disturbing  agents,  physical  and  chemical,  work  just  the  same 
effects.  The  conception  has,  indeed,  been  kept  alive  by  the  discovery 
that  electricity  is  generated  by  certain  fishes.  But  the  supposed  support 
is  wholly  imaginary.  If  because  the  Torpedo  evolves  electricity  by  the 
help  of  nerves  ramifying  through  its  electric  organ,  it  is  inferred  that 
the  nerve-force  is  electricity  ;  it  may  in  like  manner  be  inferred  that  the 
nerve-force  is  sensible  motion,  because  it  generates  sensible  motion  in 
muscles.  But,  it  may  be  asked,  do  not  the  experiments  of  Du  Bois-Rey- 
mond  yield  support  to  the  hypothesis?  A  very  doubtful  support  I 
think.  The  phenomena  he  describes  may  well  be  merely  incidental  ac- 
companiments of  actions  that  are  in  themselves  neither  electric  nor  quasi- 
electric.  The  truth  that  both  molar  and  molecular  changes  in  the  dis- 
tribution of  matter  habitually  destroy  the  electric  equilibrium,  would  be 
a  suf&cient  general  justification  for  this  belief.  But  there  is  a  special  justifl- 
7 


34  TEE  DATA  OF  PSYCHOLOGY. 

at  tlie  centre  or  at  the  periphery  lasts  an  appreciable 
time.  That  muscular  contraction  is  continuous  though  the 
stimulus  is  intermittent,  goes  to  show  tliis.  The  genesis 
of  molecular  modification  in  muscle  by  the  molecular  modi- 
fication in  the  nerve-fibres  permeating  it,  has  a  duration 
that  bridges  the  interval  between  each  pulse  of  stimulus 
and  the  next.  We  have  no  direct  proof  that  a  like  con- 
tinuity of  state  results  from  the  successive  waves  propa- 
gated to  a  nerve-centre;  for  the  actions  of  which  nerve- 
centres  are  the  seats  are  not  objectively  perceptible.  But 
we  shall  presently  find  abundant  indirect  proof  that  these 
changes  also  last  for  measurable  periods. 

This  general  truth,  like  its  predecessor,  may  be  regarded 
as  a  corollary  from  what  has  gone  before.  The  transforma- 
tions classed  as  chemical  take  time,  equally  with  those 
classed  as  isomeric.  It  is  true  that  explosions  due  to 
chemical  action  are  what  we  call  instantaneous  (a  descrip- 
tion of  them  which  is  not,  however,  scientifically  accurate; 
as  may  be  perceived  when  the  matter  exploded  is  of  con- 
cation.  Direct  proof  exists  that  the  particular  kind  of  molecular  change  we 
have  supposed  to  take  place  in  nerve,  and  in  muscle,  is  adequate  to  produce 
the  phenomena  observed  by  Du  Bois-Reymond.  Mr.  Gore  found  that  if  a 
copper-wire,  coated  with  amorphous  antimony,  formed  part  of  an  electric 
circuit,  it  happened  that  whenever  the  allotropic  change  propagated  along 
the  antimony  stopped,  the  galvanometer-needle  was  deflected.  Now,  since 
during  the  maintenance  of  a  muscular  contraction,  nerve-pulses  are  con- 
tinually arriving  and  ceasing,  and  the  muscular  fibres  (never  all  in  action 
together)  are  at  every  instant  some  of  them  contracting  and  some  relaxing, 
it  follows  that  there  will  be  a  succession  of  stoppages  of  isomeric  changes. 
Consequently  there  will  be  a  maintenance  of  deflection  in  the  galvanom- 
eter if  a  contracted  muscle  forms  part  of  the  electric  circuit. 

[Since  this  note  has  been  in  type,  1  have  referred  to  the  lecture  de- 
livered by  M.  Du  Bois-Reymond  at  the  Royal  Institution  on  April  18, 
1866,  "  On  the  Time  required  for  the  Transmission  of  Volition  and  Sen- 
tation  through  the  Iferves"  for  the  purpose  of  verifying  one  of  the 
statements  above  made ;  and  I  find  that  at  the  close  of  this  lecture  he 
goes  a  long  way  towards  abandoning  his  hypothesis.  Though  he  says,  "  it 
would  be  rash,  as  the  matter  stands,  entirely  to  dismiss  the  notion  of 
electricity  being  concerned ; "  and  though  he  sketches  out  a  theory  of 
nerve-composition  such  as  makes  it  conceivable  that  an  electric  disturb- 


NERVOUS  STIMULATION  AND  NERVOUS  DISCHARGE.     85 

siderable  bulk).  But  explosions  occur  only  in  those  excep- 
tional cases  where  the  elements  concerned  are  either,  as  in 
detonating  compounds,  distributed  among  one  another 
molecularlj,  or,  as  in  gunpowder,  with  minute  intimacy. 
In  ordinary  cases,  where  sensible  masses  of  the  elements 
concerned  are  external  to  one  another,  the  chemical  actions, 
limited  to  the  surfaces  of  contact,  proceed  with  compara- 
tive slowness.  N^ow  the  granular  protoplasm  contained 
in  and  around  nerve-vesicles,  forms,  with  its  permeating 
liquids  and  the  blood  in  adjacent  capillaries,  a  mass  of 
which  the  components  are  but  imperfectly  interfused;  and 
therefore  a  chemical  change  cannot  pass  through  it  in- 
stantly. Hence  between  the  reception  of  a  pulse  of  mole- 
cular motion  by  a  nerve-centre,  and  the  emission  of  a  gush 
of  molecular  motion,  or  discharge,  some  little  time  must 
elapse. 

§  36.  If  a  nerve-centre  that  receives  a  stimulus  through 
an  incoming  nerve,  undergoes  a  chemical  change  and  sends 

ance  might  travel  along  a  nerve  at  the  observed  rate  (basing  this,  how- 
ever, on  the  gratuitous  assumption  that  the  molecules  of  nerve-matter 
have  north  and  south  poles) ;  yet  he  admits  that  much  evidence  points 
another  way.  He  says  that  "  to  identify  it  (the  nervous  agent)  with  the 
electric  current  as  it  circulates  in  a  telegraph-wire  must  appear  hopeless, 
even  if  a  circuit,  such  as  would  be  necessary  for  the  supposed  nerve  cur- 
rent to  circulate  in,  were  anatomically  demonstrated.  Thus  to  the  other 
arguments  against  this  view  of  the  nervous  agent — that  the  resistance  of 
the  nerve-tubes  would  be  far  too  great  for  any  battery  to  send  an  available 
current  through  them — that  the  physiological  insulation  of  the  nerve-tubes 
from  each  other  would  be  impossible  to  explain — that  the  effect  of  ligature 
or  of  cutting  the  nerve  and  causing  its  ends  to  meet  again,  would  be  equally 
obscure — to  these  arguments,  unanswerable  as  they  are  in  themselves,  the  re- 
searches sketched  in  this  lecture  have  added  corroborative  evidence  of  the 
highest  order.  What  we  have  termed  the  nervous  agent,  if  we  look  upon  its 
very  small  velocity,  in  all  probability  is  some  internal  motion,  perhaps  even 
some  chemical  change,  of  the  substance  itself  contained  in  the  nerve-tubes, 
spreading  along  the  tubes,  according  to  the  speaker's  experiments,  both  ways 
from  any  point  where  the  equilibrium  has  been  disturbed ;  being  capable  of 
an  almost  infinite  number  of  variations  or  gradations,  and  of  so  peculiar  a 
character  as  to  require  the  unimpaired  condition  of  the  nervous  structure."] 


86  THE  DATA  OP  PSYCHOLOGY. 

a  discharge  along  out-going  nerves,  it  thereupon  becomes 
less  capable  of  emitting  such  discharges  in  response  to  such 
stimuli.  The  quantity  of  molecular  motion  locked  up  in  a 
nerve-centre,  is  measured  by  the  contained  quantity  of 
•unstable  nerve-matter;  and  decomposition  of  that  part  of 
the  unstable  nerve-matter  which  was  most  favourably 
placed  for  being  acted  on,  leaves  not  only  a  diminished 
quantity  but  a  quantity  that  is  less  favourably  placed  for 
being  acted  on — leaves,  therefore,  a  decreased  readiness  to 
undergo  change  when  disturbed,  as  well  as  a  decreased 
stock  of  molecular  motion  to  be  liberated.  Consequently, 
other  things  remaining  the  same,  every  excitation  of  a 
nerve-centre  reduces^  for  a  time,  its  impressibility  and  its 
energy. 

This  temporary  enfeeblement  of  a  nerve-centre,  when 
caused  by  moderate  action,  is  inconspicuous.  The  disinte- 
grated mass  quickly  re-integrates  itself  from  the  materials 
brought  by  the  blood.  But  if  the  stimulation  and  con- 
sequent discharge  are  violent,  or  if  stimulations  and  dis- 
charges are  repeated  very  rapidly,  then  repair  falls  so  far  in 
arrear  of  waste  that  partial  or  entire  incapacity  of  the 
nerve-centre  results.  All  its  unstable  substance  within 
easy  reach  of  in-coming  disturbances  has  been  decomposed; 
leaving  such  part  only  of  its  unstable  substance  as  is  most 
removed  from  disturbances,  and  can  be  affected  only  by 
excessive  ones.  A  well-known  experiment  on  the  vaso- 
motor system  of  a  frog,  may  be  cited  in  illustration.  If  a 
frog's  foot  be  placed  under  a  microscope,  and  so  adjusted 
that  the  arteries  ramifying  through  the  transparent  mem- 
brane between  the  toes  are  brought  into  view,  then,  if  a 
powerful  irritant  be  applied  to  this  membrane,  the  first 
result  observed  is  that  these  arteries  are  violently  constricted 
— the  strong  impression  conveyed  to  the  vaso-motor  centres 
there  liberates  an  excessive  discharge  along  the  fibres 
supplying  these  arteries,  causing  spasmodic  contractions  of 
their  muscular  coats.     The  second  result  is  that  these 


NERVOUS  STIMULATION  AND  NERVOUS  DISCHARGE.     87 

arteries  dilate:  losing  their  normal  contractility  they 
become  distended  with  blood,  and  the  part  is,  as  we  say, 
congested.  That  this  is  due  to  extreme  prostration  or  tem- 
porary paralysis  of  the  vaso-motor  centre,  has  been  clearly 
proved;  for  if  the  nerve-trunk  containing  the  vaso-motor 
fibres  be  dissected  out  and  artificially  irritated,  the  dilated 
arteries  instantly  contract.  How  a  nerve-centre  may  be 
prostrated  by  a  rapid  succession  of  moderate  stimuli  and 
discharges,  instead  of  by  one  violent  stimulus  and  discharge, 
is  shown  by  the  familiar  eifect  of  friction  on  the  human  skin. 
A  single  moderate  rub  causes  only  a  slight  refiex  action  on 
its  vessels,  and  leaves  the  vaso-motor  apparatus  ready  to 
act  afresh  with  no  apparent  diminution  of  power.  But  a 
series  of  rubs  is  followed  by  temporary  congestion  of  the 
vessels:  it  is  some  little  time  before  the  vaso-motor  centre 
regains  its  full  control  over  them.  And  if  the  skin  be 
continuously  chafed,  the  excessive  waste  and  debility  of 
the  vaso-motor  centre  entail  that  enduring  redness  called 
congestion.  Those  parts  of  the  nervous  system  con- 
cerned in  muscular  action,  daily  illustrate  the  same  general 
relation.  Fatigue  is  a  state  in  which  the  ability  to  generate 
motion  has  been  greatly  diminished  by  long-continued 
genesis  of  motion;  and  every  tired  horse  shows,  by  the 
small  response  he  makes  to  a  cut  of  the  whip,  that  a  more 
violent  impulse  must  be  propagated  to  the  nerve-centres  to 
cause  the  ordinary  evolution  of  nervous  energy. 

Irregularities  in  the  manifestation  of  this  truth,  are  due  to 
that  entanglement  of  the  conditions  which  was  indicated  at 
the  close  of  the  last  chapter.  It  frequently  happens,  for 
instance,  that  after  performing  its  function  for  some  time, 
a  nerve-centre  responds  to  the  demands  on  it  better  than  at 
first — a  fact  apparently  at  variance  with  the  foregoing  con- 
clusion. But  this  conclusion  supposes  all  the  circumstances 
to  have  remained  the  same ;  and  in  such  cases  they  have  not 
remained  the  same.  There  has  been  an  exaltation  of  the 
heart's  action,  or  a  local  increase  in  the  quantity  of  blood,  or 


88  THE  DATA  OP  PSYCHOLOGY. 

a  more  rapid  aeration  of  blood,  or  all  of  these.  When  every 
appliance  which  furthers  the  disintegration  and  re-integra- 
tion of  a  nerve-centre,  has  been  brought  into  full  play,  both 
waste  and  repair  go  on  faster;  and  there  result  greater 
impressibility  and  energy  than  when  the  previously-unused 
centre  contained  but  little  blood  languidly  circulating. 

§  37.  Were  Life  uniform  in  its  rate — were  terrestrial  con- 
ditions such  that  actions  of  all  kinds  could  be  performed  as 
readily  at  one  time  as  at  another,  repair  and  waste  of  all  or- 
gans, including  nervous  organs,  would  have  to  keep  an  ap- 
proximately-even pace,  one  with  the  other.  But  the  alterna- 
tion of  day  and  night  entails  an  alternation  of  greater  and  less 
facility  for  actions;  and  there  has  resulted  in  organisms  an 
adapted  alternation  in  the  relative  rates  of  waste  and  repair. 
The  adaptation  is  manifestly  due  to  survival  of  the  fittest. 
An  animal  so  constituted  that  waste  and  repair  were  balanced 
from  moment  to  moment  throughout  the  twenty-four  hours, 
would,  other  things  equal,  be  overcome  by  an  enemy  or 
competitor  that  could  evolve  greater  energy  during  the 
hours  when  light  facilitates  action,  at  the  expense  of  being 
less  energetic  during  the  hours  of  darkness  and  concealment. 
Hence  there  has  necessarily  established  itself  that  rhythmical 
variation  in  nervous  activity,  which  we  see  in  sleep  and 
waking.  Let  us  observe  how  these  are  interpretable,  the 
one  as  a  state  of  the  nervous  centres  in  which  waste  has  got 
considerably  in  excess  of  repair,  and  the  other  as  a  state  in 
which  repair  has  made  up  for  previous  excess  of  waste. 

Confining  ourselves  to  persons  whose  functional  rhythms 
have  not  been  deranged  by  undue  excitements,  we  see  that 
after  some  sixteen  or  eighteen  hours  of  sustained  impressi- 
bility and  energy,  there  is  a  diminished  readiness  to  respond 
to  stimuli  that  fall  on  the  eyes,  ears,  and  surface  of  the  body 
at  large;  and  presently  this  becomes  so  pronounced  that 
loud  sounds  and  the  irritations  produced  by  strained  atti- 
tudes, fail  to  evoke  movements.    When  great  exertion  has 


NERVOUS  STIMULATION  AND  NERVOUS  DISCHARGE.     89 

been  gone  through,  or  when  previous  intervals  of  sleep 
have  been  omitted,  the  decrease  of  impressibility  is  such 
that  tickling  the  nostrils  or  pinching  the  skin  does  nothing 
more  than  cause,  perhaps,  a  reflex  start.  This  change,  so 
marked  and  often  so  rapidly  established,  seems  greater  than 
the  alleged  cause  can  produce;  but  it  is  fully  accounted  for 
when  we  include  an  indirect  effect  of  this  cause.  The  waste 
of  the  nerve-centres  having  become  such  that  the  stimuli 
received  from  the  external  world  no  longer  suffice  to  call 
forth  from  them  adequate  discharges,  there  results  a  di- 
minished impulse  to  those  internal  organs  which  subserve 
nervous  activity,  including,  more  especially,  the  heart. 
Consequently  the  nerve-centres,  already  working  feebly, 
are  supplied  with  less  blood  and  begin  to  work  more  feebly — 
respond  still  less  to  impressions,  and  discharge  still  less  to 
the  heart.  And  so  the  two  act  and  re-act  until  there  is 
reached  this  state  of  profound  unimpressibility  and  inactivity. 

Between  this  state  and  the  waking  state,  the  essential 
distinction  is  a  great  reduction  of  waste.  Certainly  in  some 
nervous  centres  and  probably  in  all,  waste  does  not  abso- 
lutely cease:  there  continue  those  emissions  of  force  which 
keep  up  the  vital  processes;  and  it  is,  I  think,  unlikely  that 
there  is  ever  an  entire  stoppage  of  those  changes  which  take 
place  in  the  highest  centres.  But  the  rate  of  waste  falls  so 
low  that  the  rate  of  repair  exceeds  it.  It  is  not  that  during 
the  period  of  activity  waste  goes  on  without  repair,  while 
during  the  period  of  inactivity  repair  goes  on  without  waste; 
for  the  two  always  go  on  together.  Very  possibly — probably 
even — repair  is  as  rapid  during  the  day  as  during  the  night: 
perhaps  even  more  rapid:  for  the  blood  is  on  the  average 
richer  and  circulates  faster.  But  during  the  day  the  loss  is 
greater  than  the  gain,  whereas  during  the  night  the  gain  is 
diminished  by  scarcely  any  loss.  Hence  results  accumula- 
tion :  there  is  a  restoration  of  the  nerve-tissue  to  its  state  of 
integrity. 

In  the  course  of  some  hours  this  restoration  begins  to 


90  THE  DATA  OF  PSYCHOLOGY. 

show  its  effects  in  returning  impressibility.  WHle  in 
sleepiness  we  see  a  decreasing  readiness  to  respond  to  ex- 
ternal stimuli,  the  approach  to  a  waking  state  is  character- 
ized by  an  increasing  readiness  to  respond  to  external  stimuli. 
Throughout  the  period  of  quiescence  the  afferent  nerves 
remain  subject  to  incident  forces.  The  pressure  of  the  body 
on  the  bed  affects  some  of  them,  and  others  are  affected  by 
the  touch  of  the  bed-clothes;  degrees  of  heat  a  little  above 
or  below  the  average,  act  on  others;  and  yet  others  receive 
sonorous  vibrations  constantly  occurring.  But  whereas 
sleep  results  because  the  centres  worn  by  action  become 
less  and  less  sensitive  to  these  stimuli,  waking  results 
because  the  centres  repaired  during  rest  become  more  and 
more  sensitive  to  them.  The  strains  of  muscles  and  liga- 
ments which  during  the  first  part  of  the  night  fail  to  cause 
changes  of  attitude,  cause  such  changes  towards  morn- 
ing. The  amount  of  light  that  traverses  the  eye-lids  pre- 
sently suffices  to  call  forth  movements.  Some  slight  noise 
which,  hours  before,  would  have  had  no  effect,  now  produces 
a  start.  Even  in  the  absence  of  external  stimuli  (which, 
however,  can  never  be  absent)  there  are  the  stimuli  from  the 
viscera,  and  especially  from  the  alimentary  canal :  an  empty 
stomach  eventually  sends  to  the  cerebro-spinal  system 
enough  disturbance  to  end  the  quiescent  state.  The  longer 
repair  goes  on  unopposed  by  appreciable  waste,  the  greater 
must  become  the  instability  of  the  nerve-centres,  and  the 
greater  their  readiness  to  act;  so  that  there  must  at  length 
come  a  time  when  the  slightest  impressions  will  produce 
motions.  Such  impressions,  however  slight,  are  necessary 
antecedents.  The  re-integrated  nerve-centres  do  not  resume 
their  activity  until  an  impulse  arriving  from  the  periphery 
overthrows  some  of  their  molecules.  Evidence  of  this  is 
furnished  to  most  every  morning.  On  awakening  from 
refreshing  sleep,  there  commonly  occurs  an  involuntary 
stretching  of  the  muscles  of  the  whole  body;  showing  an 
immense  undirected  motor  discharge.    But  this  is  not  the 


NERVOUS  STIMULATION  AND  NERVOUS  DISCHARGE.     91 

initial  fact.  No  one  awakes  to  find  himself  then  and  there 
stretching;  which  might  happen  were  the  discharge  spon- 
taneous. It  comes  after  those  stronger  disturbances  that 
are  propagated  to  the  centres,  as  soon  as  some  slight  distur- 
bance has  led  to  the  slight  movements  that  accompany 
waking.  A  trifling  sound  causes  opening  of  the  eyes  and 
a  turn  of  the  head.  Thereupon  follow  vivid  impressions 
through  the  eyes,  through  the  skin  that  rubs  against  the 
bed-clothes,  and  through  the  muscles  that  set  up  the 
movements.  And  a  relatively-large  aggregate  of  stimuli 
being  sent  from  the  periphery,  there  results  this  relatively- 
large  gush  of  motor  excitement. 

On  pursuing  the  argument  we  may  understand  why  the 
energies  continue  to  rise  for  some  time  after  waking. 
We  saw  that  when  once  sleepiness  has  commenced,  it 
increases  because  in  proportion  as  the  nervous  centres  fail 
in  their  discharges,  the  heart,  losing  part  of  its  stimulus, 
begins  to  flag,  and  that  the  flagging  of  the  heart  leads  to  a 
greater  inertness  of  the  nerve-centres,  which  re-acts  as 
before.  Conversely,  it  will  here  be  manifest  that  when  the 
nerve-centres,  repaired  by  sleep,  become  again  ready  for 
discharging  with  vigour,  there  take  place  an  action  and  re- 
action which  have  the  opposite  effect.  The  pulsations  on 
awaking  are  comparatively  feeble.  As  soon  as  stimuli  begin 
to  be  received  through  the  sensory  organs,  and  the  discharges 
of  the  nerve-centres  are  renewed,  the  heart  comes  in  for  its 
share  of  these  and  acts  more  vigorously.  By  so  doing  it  sup- 
plies the  nerve-centres  with  more  blood  in  quicker  gushes. 
A  greater  nervous  discharge  is  thereby  made  possible,  which 
again,  among  other  results,  exalts  the  heart's  action.  And 
so  the  mutual  aid  goes  on:  the  greatest  nervous  vigour 
being  reached  when  the  vascular  activity  has  been  still 
further  raised  by  a  meal,  and  the  blood  has  been  enriched 
by  the  absorbed  materials. 

§  38.  As  implied  by  much  that  has  gone  before,  and  as 


92  THE  DATA  OP  PSYCHOLOGY. 

especially  implied  by  the  last  section,  nervous  stimulation 
and  nervous  discharge  have  always  both  special  and  general 
results.  Beyond  the  primary  and  definite  effect  wrought  on 
a  particular  part  by  a  particular  impression,  there  are  in 
every  case  secondary  and  indefinite  effects  diffused  through  the 
whole  nervous  system,  and  by  it  through  the  body  at  large. 
It  was  pointed  out  (§§  10, 11)  that  the  simplest  nerve-cen- 
tre puts  in  relation  not  afferent  and  efferent  fibres  alone; 
but  that  through  other  fibres,  commissural  and  centripetal, 
connections  are  made  between  it  and  other  nerve-centres  of 
the  same  grade  and  of  a  higher  grade.  Further,  we  saw  that 
when  such  a  nerve-centre  is  excited  through  an  afferent 
nerve,  the  disengaged  molecular  motion  does  not  escape 
wholly  along  one  or  more  efferent  nerves;  but  that  part  of 
it,  propagated  to  higher  centres,  there  sets  up  supplemen- 
tary changes.  The  diffusion  does  not  stop  here — remoter 
parts  are  reached;  and  thus  the  disturbance  of  a  single 
nerve-fibre,  if  at  all  considerable,  reverberates  throughout 
the  entire  nervous  system,  and  affects  all  the  functions  con- 
trolled by  it.  Digging  a  pin  into  the  foot  may  cause  a  con- 
vulsive contraction  not  of  the  leg-muscles  only,  but  of 
many  other  muscles  throughout  the  body.  At  the  same 
time  it  may  alter  the  rate  of  pulsation,  and  send  waves  of 
constriction  along  the  arteries.  The  excreting  structures 
of  the  skin  may  be  so  affected  that  a  burst  of  perspiration 
results;  and  the  actions  going  on  throughout  the  alimentary 
canal  may  be  deranged.  Such  reverberations,  which  become 
conspicuous  when  the  disturbances  are  decided,  take  place 
also  when  they  are  slight.  A  more  vivid  light,  causing 
as  it  does  stronger  pulses  of  change  through  the  optic  nerve, 
increases  the  rate  of  respiration;  and  doubtless  the  other 
vital  functions  are  simultaneously  exalted.  So  that  each 
nervous  impression,  beyond  a  direct  response  in  the  shape 
of  increased  action  from  one  or  more  organs,  calls  forth  an 
indirect  response  in  the  shape  of  increased  action  of  the 
organism  as  a  whole. 


NERVOUS  STIMULATION  AND  NERVOUS  DISCHARGE.     93 

Remembering  that  every  instant  the  disturbance  thus 
echoing  throughout  all  passages  of  the  nervous  system  is 
not  solitary,  but  that  there  are  many  such  disturbances,  here 
arising  from  pressure  there  from  touch,  in  this  place  pro- 
duced by  sound  and  in  that  by  light,  at  one  part  by  mus- 
cular strain  and  at  another  by  heat  or  cold;  it  will  be 
manifest  that,  besides  the  few  distinct  waves  of  nervous 
change  working  their  distinct  effects,  there  are  multitudinous 
indistinct  waves,  secondary  and  tertiary,  travelling  in  all 
directions  working  their  indistinct  effects. 

§  39.  Since  such  reflected  and  re-reflected  disturbances 
everywhere  act  as  stimuli,  we  must  regard  the  entire 
nervous  system  as  at  all  times  discharging  itself.  The 
unstable  molecules  of  its  centres,  exposed  to  this  confused 
reverberation,  are  liable  to  be  decomposed  wherever  a 
concurrence  of  small  waves  makes  the  local  agitation  con- 
siderable ;  and  the  molecular  motion  thereupon  disengaged, 
adds  to  the  centrifugal  gush  perpetually  going  on.  Rightly 
to  conceive  nervous  action  then,  we  must  think  of  the  con- 
spicuous emissions  of  force  from  parts  of  the  nervous 
system  that  are  strongly  disturbed,  as  standing  out  from 
a  vague  back-ground  of  inconspicuous  emissions  from  the 
whole  nervous  system,  which  is  slightly  disturbed. 

To  this  general  nervous  disturbance  with  its  consequent 
general  discharge,  is  probably  due  a  certain  general  action 
of  the  motor  organs,  ^o  muscles  are  ever  in  a  state  of 
absolute  rest.  What  we  distinguish  as  muscular  motion 
is  produced  by  the  greater  contraction  of  some  muscles  than 
of  others.  The  others,  however,  are  all  slightly  contracted; 
and  would  severally  produce  motion  were  they  not  balanced 
or  out-balanced  by  their  antagonist  muscles.  This  per- 
vading activity  of  the  muscles  is  called  their  tonic  state. 
And  while  we  regard  particular  contractions  as  the  results 
of  particular  nervous  discharges,  we  have  good  reasons  for 
concluding  that  this  universal  contraction  is  the  result 


94  THE  DATA  OF  PSYCHOLOGY. 

of  the  universal  nervous  discharge.  Here  are  a  few  of 
them.  Sleep,  as  above  explained,  implies  dimi- 

nished nervous  discharge,  special  and  general.  A  dimi- 
nution of  the  general  discharge  ought,  then,  to  be  shown 
in  a  decrease  of  the  tonic  contraction.  It  is  so  shown. 
Falling  asleep  is  accompanied  by  muscular  relaxation: 
though  previously  the  attitude  was  such  that  no  effort 
seemed  requisite  to  maintain  it;  yet  that  there  was 
some  muscular  strain,  and  that  it  has  suddenly  become 
less,  is  proved  by  the  sliding  down  of  a  limb,  or  of 
the  head,  to  a  more  stable  position.  Certain  dis- 

orders, as  palsy,  yield  further  proof.  The  flexors  and 
extensors  which,  when  duly  contracted,  serve  by  their 
balanced  antagonism  to  hold  a  limb  steady,  cease  to  do  this 
when  the  general  nervous  discharge  is  not  great  enough  to 
keep  them  and  all  other  muscles  braced  up:  in  default  of 
sufficient  stimulus  for  both,  now  one  set  and  now  the  other 
fails  to  put  the  due  check  on  its  opponent.  That  such 
shakings  are  so  caused,  we  see  clearly  in  persons  debilitated 
by  over-stimulation;  for  in  them  this  symptom  may  be 
temporarily  mitigated,  or  almost  cured,  by  temporarily  in- 
creasing the  general  nervous  discharge.  The  drunkard  who 
early  in  the  day  cannot  lift  his  glass  without  spilling  the 
contents,  is  able  to  do  this  after  his  brain  has  been  excited 
by  the  usual  doses  of  alcohol. 

Of  course  it  is  not  the  muscles  alone  on  which  this  con- 
tinuous centrifugal  gush  is  expended.  Through  the  inter- 
mediation of  nerves  connecting  the  cerebro-spinal  system 
with  the  sympathetic  system,  the  viscera  receive  their  share 
of  it.  Hence  the  overflow  of  nervous  energy  which,  without 
special  solicitations,  diffuses  itself  throughout  the  motor 
structures,  giving  elasticity  to  the  step,  and  producing  the 
concave  bend  of  the  back,  the  opened-out  shoulders,  the 
raised  head,  &c.,  has,  for  its  simultaneous  results,  an  accel- 
erated circulation,  an  invigorated  digestion,  and  an  exalta- 
tion of  the  vital  processes  at  large. 


NERVOUS  STIMULATION  AND  NERVOUS  DISCHARGE,     95 

§  40.  Briefly  reviewed  from  a  somewliat  different  stand- 
point, the  following  are  the  leading  facts  which  it  concerns 
us  to  remember. 

Nervous  stimulations  and  discharges  consist  of  waves  of 
molecular  change,  that  chase  one  another  rapidly  through 
nerve-fibres.  The  stimulus  or  discharge  formed  of  such 
waves,  arises  at  some  place  where  unstable  nerve-substance 
has  been  disturbed;  and  is  the  same  no  matter  what  agent 
caused  the  disturbance.  The  successive  waves  severally 
travel  with  a  velocity  which,  though  considerable  compared 
with  ordinary  sensible  motions,  is  extremely  slow  compared 
with  other  kinds  of  transmitted  molecular  motions.  And 
each  set  of  waves,  while  itself  caused  by  the  decomposition 
of  unstable  nerve-matter,  is  a  means  of  decomposing  other 
unstable  nerve-matter:  so  generating  further  and  often 
stronger  sets  of  waves,  which  similarly  chase  one  another 
into  many  and  distant  parts  of  the  nervous  system. 

There  is  a  triple  rhythm  in  these  nervous  stimulations 
and  discharges — each  form  of  rhythm  being  due  to  the 
greater  or  less  incapacity  for  action  which  an  action  produces. 
We  have  seen  that  every  wave  of  isomeric  transformation 
passing  along  a  nerve-fibre,  entails  on  it  a  momentary  unfit- 
ness to  convey  another  wave;  and  that  it  recovers  its  fitness 
only  when  its  lost  molecular  motion  has  been  replaced  and  its 
unstable  state  thus  restored.  "We  have  also  seen  that  any 
portion  of  grey  matter  in  a  nerve-centre,  which  having  been 
disturbed  and  partially  decomposed  has  emitted  a  shock  of 
molecular  change,  is  proportionately  incapacitated ;  and  that 
it  recovers  its  original  ability  only  as  fast  as  it  re-integrates 
itself  from  the  materials  brought  by  the  blood.  And  then 
there  comes  the  further  rhythm  constituted  by  the  alterna- 
tions of  sleep  and  waking — a  rhythm  having  the  same  ori- 
gin as  the  last,  and  being  supplementary  to  it. 

The  remaining  truth  which  we  have  contemplated  is  that 
each  special  stimulation  and  the  special  discharge  produced 
by  it,  do  not  together  form  the  whole  of  every  nervous  act; 


96  THE  DATA  OP  PSYCHOLOGY. 

but  that  there  is  always  an  accompanying  general  stimula- 
tion and  general  discharge.  Every  part  of  the  nervous 
system  is  every  instant  traversed  by  waves  of  mole- 
cular change — here  strong  and  here  feeble.  There  is  a 
universal  reverberation  of  secondary  waves  induced  by 
the  stronger  primary  waves,  now  arising  in  this  place  and 
now  in  that;  and  each  nervous  act  thus  helps  to  excite  the 
general  vital  processes  while  it  achieves  some  particular 
vital  process.  The  recognition  of  this  fact  discloses  a  much 
closer  kinship  between  the  functions  of  the  nervous  system 
and  the  organic  functions  at  large,  than  appears  on  the  sur- 
face. Though  unlike  the  pulses  of  the  blood  in  many 
respects,  these  pulses  of  molecular  motion  are  like  them 
in  being  perpetually  generated  and  diffused  throughout  the 
body;  and  they  are  also  like  them  in  this,  that  the  cen- 
tripetal waves  are  comparatively  feeble  while  the  centrifugal 
waves  are  comparatively  strong.  To  which  analogies  must 
be  added  the  no  less  striking  one,  that  the  performance  of 
its  office  by  every  part  of  the  body,  down  even  to  the  small- 
est, just  as  much  depends  on  the  local  gushes  of  nervous 
energy  as  it  depends  on  the  local  gushes  of  blood. 


CHAPTEE  YI. 


iESTHO-PHYSIOLOGT/ 


§  41.  Througliout  the  foregoing  chapters  nervous  pheno- 
mena have  been  formulated  in  terms  of  Matter  and  Motion. 
If  from  time  to  time  the  phrases  used  have  tacitly  referred 
to  another  aspect  of  nervous  phenomena,  the  tacit  references 
have  formed  no  parts  of  the  propositions  set  down;  but  have 

•  This  new  word  will  possibly  be  condemned  as  not  legitimately  com- 
pounded. The  objection  that  the  root  from  which  its  prefix  is  derived,  is 
shorn  of  its  fair  proportions,  admits,  I  am  told,  of  a  satisfactory  answer : 
from  the  proximate  root,  appeal  may  be  made  to  the  original  root,  which, 
following  the  Greek  method  of  forming  derivatives,  would  admit  of  the 
required  modification.  But  to  the  criticism  that  the  word  involves  the 
logical  inconsistency  of  uniting  a  verb  with  a  noun,  there  is  no  such  suffi- 
cient answer.  Nevertheless,  I  deliberately  adopt  ^stho-pTiysiology  in  pre- 
ference to  the  more  cumbrous  and  cacophonous  JEsthesi-phyaiology.  A 
prog^ssive  integration  by  which  the  originally-distinct  and  numerous  parts 
of  compound  words  become  fused  together,  blurred,  and  some  of  them  lost, 
is  one  of  the  essential  processes  in  the  development  of  language.  If  man- 
kind had  refrained  from  the  obliteration  and  disfigurement  of  roots,  and 
parts  of  roots,  language  would  have  continued  wholly  inadequate  for  all  but 
its  simplest  functions.  Omitting  those  formed  by  onomatopoeia,  the  best 
words  are  those  from  which  long  use  has  worn  away  all,  or  nearly  all,  traces 
of  their  origin.  We  may  as  well,  therefore,  begin  with  abbreviated  and 
modified  words  when  we  have  to  coin  them ;  instead  of  leaving  time  to 
bring  about  the  needful  shortening  and  shaping.  Those^whordeSlIngwrfR" 
words  as  counters,  see  that  their  convenience  as  counters  is  the  chief  con- 
sideration, will  probably  coincide  in  this  view ;  though  I  suppose  it  will 
be  wholly  disapproved  by  those  who  regard  words  not  as  counters  but  as 
money.  -• 


98  THE  DATA  OF  PSYCHOLOGY. 

been  due  to  lack  of  fit  words — words  free  from  unfit  associa- 
tions. As  already  said,  the  nervous  system  can  be  known 
only  as  a  structure  that  undergoes  and  initiates  either  visi- 
ble changes,  or  changes  that  are  representable  in  terms 
furnished  by  the  visible  world.  And  thus  far  we  have 
limited  ourselves  to  generalizing  the  phenomena  which  it 
thus  presents  to  us  objectively. 

Now,  however,  we  turn  to  a  totally-distinct  aspect  of  our 
subject.  There  lies  before  us  a  class  of  facts  absolutely 
without  any  perceptible  or  conceivable  community  of  nature 
with  the  facts  that  have  occupied  us.  The  truths  here  to  be 
set  do^vn  are  truths  of  which  the  very  elements  are  unknown 
to  physical  science.  Objective  observation  and  analysis  fail 
us;  and  subjective  observation  and  analysis  must  supple- 
ment them. 

In  other  words,  we  have  to  treat  of  nervous  phenomena 
as  phenomena  of  consciousness.  The  changes  which,  re- 
garded as  modes  of  the  Non-Ego^  have  been  expressed  in 
terms  of  motion,  have  now,  regarded  as  modes  of  the  Ego^ 
to  be  expressed  in  terms  of  feeling.  Having  contemplated 
these  changes  on  their  outsides,  we  have  to  contemplate 
them  from  their  insides.  To  speak  with  exactness,  indeed, 
it  cannot  be  said  that  we  have  so  to  contemplate  these 
changes;  for  this  expression  implies  that  these  changes  can 
be  simultaneously  seen  by  more  than  one,  which  is  not 
true.  Rigorously  limiting  the  proposition  to  that  which  is 
alone  possible,  it  amounts  to  this: — I  have  to  describe  the 
laws  of  relation  between  the  states  of  feeling  occurring  in 
my  own  consciousness,  and  the  physical  affections  of  that 
nervous  system  which  I  conclude  I  possess;  and  the  reader 
has  to  observe  whether  in  himself  there  exist  parallel  rela- 
tions between  such  known  states  of  consciousness  and  such 
supposed  nervous  affections. 

This  will  perhaps  be  thought  a  needlessly  roundabout,  if 
not  a  sceptical,  statement;  but  it  is  in  fact  not  roundabout 
enough.     It  does  not  bring  sufficiently  into  view  the  re- 


^STHO-PHYSIOLOGY.  99 

motely-inferential  character  of  the  belief  that  feeling  and 
nervous  action  are  correlated.  Before  proceeding  on  this 
belief,  let  us  observe  how  indirect  is  the  path  which  leads  to 
it. — 1.  Each  individual  is  absolutely  incapable  of  knowing 
any  feelings  but  his  own.  That  there  exist  other  sensations 
and  emotions,  is  a  conclusion  implying,  in  the  first  place, 
the  reasonings  through  which  he  identifies  certain  objects 
as  bodies  of  like  nature  with  his  own  body;  and  implying, 
in  the  second  place,  the  further  reasonings  which  convince 
him  that  along  with  the  external  actions  of  these  bodies, 
there  go  internal  states  of  consciousness  like  those  accom- 
panying such  external  actions  of  his  own  body.  2.  This 
conclusion  that  there  exist  beings  like  himself,  and  that 
under  like  conditions  they  experience  like  feelings,  even 
supposing  it  entirely  true  (and  it  is  not  entirely  true,  for 
many  facts  unite  to  prove  that  under  like  conditions  both 
the  quantities  and  the  qualities  of  sensations  and  emotions 
in  different  individuals  differ  considerably),  by  no  means 
implies  that  what  he  knows  under  its  subjective  aspect 
as  feeling,  is,  under  its  objective  aspect,  nervous  action. 
The  average  observer  has  no  direct  evidence  that  these 
other  Kke  beings  have  nervous  systems,  any  more  than  that 
he  has  himself  a  nervous  system;  and  he  has  no  direct 
evidence  in  the  one  case  any  more  than  in  the  other,  that 
nervous  excitations  are  the  causes  of  feelings.  Experi- 
mental physiologists  and  pathologists  only  have  proofs ;  and 
even  their  proofs  are  mostly  indirect.  The  experiments 
which  yield  them  are  usually  made  on  beings  of  another  and 
much  inferior  order.  The  contractions  of  muscles  and 
arteries,  caused  by  irritating  nerve-trunks  in  frogs,  the 
convulsive  movements,  and  sometimes  the  sounds,  made  by 
birds  and  mammals  whose  nerve-centres  are  variously  in- 
jured— these  are  the  phenomena  from  which  it  is  inferred 
that  the  human  nervous  system  is  the  seat  of  the  human  feel- 
ings, and  that  these  feelings  are  the  correlatives  of  its  ex- 
citations: the  only  important  verifications  of  the  inference 
8 


100  THE  DATA  OP  PSYCHOLOGY. 

being  those  obtained  during  surgical  operations  where  nerve- 
trunks  are  cut  through,  and  those  furnished  hjj)ost  mortem 
examinations  of  morbid  nervous  structures  in  the  bodies  of 
those  who  when  alive  displayed  abnormal  excesses  or  defects 
of  feeling.  3.  And  then,  having  learnt  at  second  hand, 
through  the  remotely-inferential  interpretation  of  verbal 
signs,  that  in  now  one  and  now  another  of  the  bodies  he 
recognizes  as  like  his  own  there  has  been  found  a  nervous 
system,  and  that  the  stimulations  of  this  produce  those  mani- 
festations which  in  himself  accompany  feelings,  the  reader 
imagines  a  nervous  system  contained  in  his  own  body,  and 
concludes  that  his  sensations  and  emotions  are  due  to  the  dis- 
turbances which  the  outer  world  sets  up  at  its  periphery,  and 
arouses  by  indirect  processes  in  its  centres.  Such,  stated  as 
briefly  as  possible,  is  the  long  and  involved  series  of  steps 
by  which  alone  the  connection  between  nervous  action  and 
feeling  can  be  established. 

Nevertheless,  the  evidence  of  this  connection  is  so  large 
in  amount,  presents  such  a  congruity  under  so  great  a 
variety  of  circumstances,  and  is  so  continually  confirmed  by 
the  correct  anticipations  to  which  it  leads,  that  we  can 
entertain  nothing  more  than  a  theoretical  doubt  of  its  truth. 
Here  accepting  the  belief,  alike  popular  and  scientific,  that 
all  the  human  beings  known  objectively  have  feelings  like 
those  which  each  knows  subjectively;  and  accepting  also 
the  belief,  originating  with  science  but  now  diffused  through 
the  general  mind,  that  feelings  are  the  concomitants  of 
nervous  changes;  we  will  proceed  to  consider  the  relation 
between  feelings  and  nervous  changes  under  its  leading 
aspects. 

§  42.  And  first  let  us  observe  that  the  circumstances 
conducive  to  the  one  are  identical  with  the  circumstances 
conducive  to  the  other.  The  conditions  which  we  before 
found  essential  to  the  production  of  nervous  action,  we  shall 
now  find  essential  to  the  production  of  feeling.  We  may  pass 


-SISTHO-PHYSIOLOGY.  101 

over  the  evidences  briefly,  as  being  many  of  them  the  inner 
aspects  of  phenomena  already  observed  under  their  outer 
aspects. 

That  without  continuity  of  nerve-fibre  between  periphery 
and  centre,  a  disturbance  at  the  one  causes  no  feeling  at  the 
other,  is  proved  to  every  one  who  has  cut  himself  deeply: 
for  a  long  time  the  part  that  has  had  its  nervous  com- 
munication destroyed,  remains  numb.  This  experience, 
usually  very  limited  in  each  person,  is  borne  out  by  the 
testimony  of  those  seriously  injured;  and  especially  by  the 
testimony  of  those  whose  sensations  over  large  parts  of 
their  bodies  have  ceased,  and  who,  after  death,  are  found 
to  have  lesions  in  the  conducting  structures  of  the  nervous 
centres. 

The  hindrance  or  prevention  of  feeling  by  pressure,  is 
illustrated  by  the  numbness  of  a  limb  so  placed  that  its 
whole  weight,  and  perhaps  the  weight  of  another  limb 
lying  over  it,  comes  on  the  edge  say  of  a  table;  so  that 
great  stress  is  borne  by  some  portion  of  the  chief  nerve- 
trunk.  Local  anaesthesia  thus  caused  in  strong  persons, 
is  caused  still  more  readily  in  feeble  persons;  who,  on 
awaking,  not  unf requently  find  complete  insensibility  of  the 
parts  that  have  been  pressed  against  the  bed  during  sleep. 

Ability  to  feel  depends  on  the  maintenance  of  a  certain 
temperature.  This  also  is  a  general  truth  of  which  some 
proof  is  furnished  to  every  individual  by  his  own  experience 
— or,  at  any  rate,  to  every  individual  inhabiting  a  climate 
where  the  winter's  frost  suffices  greatly  to  chill  the  ex- 
tremities. Evidence  much  stronger  but  indirect,  is  given 
him  by  those  who  have  undergone  surgical  operations  in 
parts  deprived  of  feeling  by  freezing  mixtures  or  by  ether- 
spray.  Loss  of  local  sensibility  from  local  cold,  ordinarily 
not  very  manifest  unless  the  cold  is  great,  becomes  manifest 
when  the  cold  is  slight  if  the  circumstances  .supply  a  delicate 
test.  This  is  interestingly  shown  among  compositors.  The 
air  of  a  printing-office  has  to  be  kept  very  warm,  even  at 


UNtvERsrrY  OP  cjvuforni^ 


AUY 


102  THE  DATA  OF  PSYCHOLOGY. 

the  expense  of  unhealthy  closeness;  otherwise  the  fingers 
of  the  compositors  cease  to  lay  hold  of,  and  manipulate, 
the  types  with  the  requisite  nicety  and  speed. 

Few  persons  have  immediate  experience  of  the  fact  that 
defect  of  blood  in  a  part  causes  defective  sensibility  of  that 
part;  but  all  persons  have  immediate  experience  of  the 
local  exaltation  of  sensibility  that  accompanies  local  excess 
of  blood.  The  inflamed  neighbourhood  of  a  wound,  or 
even  the  surface  of  a  pimple,  yields  to  consciousness  when 
touched,  an  amount  of  feeling  far  greater  than  is  yielded  by 
a  part  of  the  skin  supplied  with  the  ordinary  amount  of 
blood.  Special  organs  of  touch  show  us  well  the  increased 
sensitiveness  thus  caused.  When  one  of  those  sacs  con- 
taining the  bulbs  of  the  small  hairs  scattered  over  the  skin, 
is  congested,  the  rubbing  of  the  clothes  against  the  hair 
growing  from  it,  especially  if  it  has  been  broken  short,  pro- 
duces an  unbearable  smart.  Among  evidences  yielded  by 
the  other  senses,  a  familiar  one  is  the  intolerance  of  light 
that  goes  along  with  inflammation  of  the  eyes.  And  there 
is  an  unfamiliar  one  particularly  worth  noting,  because 
it  exhibits  the  effect  due  to  increased  quantity  of  blood 
apart  from  increased  temperature.  The  observation  may 
be  made  when  taking  a  hot  bath.  Let  the  water  be  above 
blood-heat — say  100°  Fh.  After  remaining  quiet  for  a  time 
until  equally  heated  all  over,  stand  up  and  rub  one  por- 
tion of  the  body  with  a  flesh-brush  until  it  is  red.  Pause 
a  few  moments,  and  lie  down  again  in  the  water.  It  will 
then  be  perceived  that  to  the  reddened  part  the  water  seems 
much  hotter  than  it  does  to  any  other  part.* 

That  degree  of  feeling  is  affected  by  quality  of  blood  as 
well  as  by  quantity,  is  a  truth  not  easily  discerned  within  the 

*  This  fact  yields  proof,  if  there  needs  any,  that  the  nerves  which 
appreciate  temperature  are  not  the  nerves  of  touch.  Violent  friction  must 
produce  a  momentary  incapacity  of  the  nerves  of  touch ;  and  this  in- 
capacity would  be  shown  in  a  decreased,  instead  of  an  increased,  appre- 
ciation of  temperatnre,  were  they  the  agents  concerned. 


^STHO-PHYSIOLOGY.  103 

experiences  of  each  individual,  if  attention  is  limited  to  those 
variations  of  feeling  that  accompany  naturally-produced 
variations  in  quality  of  blood.  For  such  variations  cannot 
be  identified  with  precision;  and  they  arise  so  slowly  that  the 
concomitant  mental  states  cannot  be  brought  into  close  con- 
tiguity, so  as  to  bring  out  their  contrasts  clearly.  But  by 
making  certain  artificial  additions  to  the  blood,  every  one 
gets  proof  of  the  connection  between  its  quality  and  the 
genesis  of  feeling.  The  effects  of  stimulants  on  conscious- 
ness are  mostly  traced  in  the  intensification  of  those  in- 
ternally-initiated feelings  with  which  we  shall  deal  pre- 
sently; but  they  may  also  sometimes  be  traced  in  the 
intensification  of  the  externally-initiated  feelings.  In 
nervous  subjects,  ordinary  impressions  on  the  senses 
are  often  rendered  abnormally  acute  by  tonics.  When 
under  the  influence  of  opium,  music  that  was  previously 
unenjoyed  may  be  greatly  enjoyed;  and  it  is  a  well-known 
result  of  hashish  to  give  an  excessive  vividness  to  the 
sensations. 

How,  contrariwise,  there  are  substances  which,  when 
added  to  the  blood,  render  sentiency  less  vivid,  is  shown 
by  other  facts  similarly  reached.  We  have  sedative 
medicines — medicines  that  diminish  the  amounts  of  painful 
consciousness  caused  by  irritations  at  the  periphery  of 
the  nervous  system.  And  we  have  agents  of  the  same 
class  called  anaesthetics,  which,  in  a  still  greater  degree, 
hinder  the  genesis  of  feelings  by  the  actions  that  usu- 
ally generate  them.  These  effects  so  caused,  help  us  to 
understand  the  stupor  produced  by  the  natural  anaesthetics, 
carbonic  acid  and  urea;  and  prove  that  some  variations 
in  degree  of  feeling  are  determined  by  variations  in  the 
activities  of  excreting  organs. 

§  43.  Now  that  we  have  noted  how  feelings  and  nervous 
changes  are  facilitated  or  hindered  by  the  same  conditions, 
we  may  go  on  to  collate  them  in  detail.    Let  us  begin  by  die- 


104  THE  DATA  OF  PSYCHOLOGY. 

tinguishing  those  nervous  changes  which  are  accompanied 
by  feehngs  from  those  which  are  not.  For,  as  we  noted  in 
passing,  several  classes  of  them  have  objective  aspects  only 
— do  not  present  inner  faces  to  consciousness;  and  others 
have  subjective  aspects  in  early  life  but  cease  to  have  them 
in  adult  life. 

Chief  among  the  nervous  changes  that  have  no  identifi- 
able subjective  aspects,  are  those  occurring  in  the  visceral 
nervous  system.  So  long  as  they  are  normal  in  their 
amounts,  the  stimulations  and  discharges  of  which  the 
sympathetic  is  the  seat,  go  on  without  sensations;  and  even 
when  abnormal,  the  resulting  discomfort  or  pain  is  probably 
not  due  to  them  but  to  disturbance  of  those  cerebro-spinal 
fibres  which  accompany  the  sympathetic  through  all  its 
branchings.  Similarly  with  the  local  ganglia  and  fibres  of 
the  heart.  Ordinarily  there  is  no  consciousness  of  the  heart's 
action ;  and  even  when  the  pulsations  are  violent,  the  modi- 
fications of  consciousness  do  not  arise  from  the  state  of  the 
heart's  nervous  system,  but  from  disturbance  of  cerebro- 
spinal nerves  caused  by  the  bounds  of  the  heart  against  ad- 
jacent structures.  The  like  holds  with  the  vaso-motor  nerves. 
Under  ordinary  conditions  these  regulate  the  diameters  of 
the  arteries  without  our  knowing  anything  about  it;  and 
though  where,  as  in  a  blush,  great  dilatation  of  the  vessels 
has  been  produced,  we  are  made  aware  of  their  action,  yet 
we  are  made  aware  of  it  indirectly,  through  the  local  change 
in  the  quantity  of  blood  and  the  consequent  effect  on  the 
nerves  that  appreciate  temperature. 

The  majority  of  stimulations  and  discharges  occurring  in 
the  spinal  cord,  have  subjective  accompaniments.  These, 
however,  are  not  localized  at  those  points  in  the  spinal  cord 
where  the  essential  nervous  changes  take  place;  as  is 
proved  by  the  fact  that  when  some  lesion  of  the  spinal 
cord  which  has  not  injured  its  lower  part,  has  cut  off  com- 
munication with  the  brain,  the  reflex  acts  performed  by  this 
lower  part  are  unconscious.    Proceeding  upon  the  inference 


^STHO-PHYSIOLOGY.  105 

before  drawn  (§21)  that  when  a  wave  of  disturbance 
brought  by  an  afferent  nerve  to  a  spinal  centre,  liberates  a 
quantity  of  molecular  motion,  a  portion  of  it,  not  discharged 
along  the  efferent  nerves,  is  propagated  through  a  centri- 
petal nerve  to  a  higher  centre,  we  may  conclude  that  it  is 
this  portion  which  comes,  in  the  higher  centre,  to  have  a 
subjective  aspect  as  a  sensation:  being  there  joined  with 
other  sensations  and  feelings  of  other  orders  into  a  chain 
of  states  of  consciousness,  out  of  which  no  sensation  is  ever 
known  to  exist.  For  recognition  of  a  sensation  as  such  or 
such,  necessitates  the  bringing  of  it  into  relation  with  the 
continuous  series  of  sentient  states,  from  some  of  which, 
simultaneously  experienced,  it  is  dissociated  by  perceived 
unlikeness,  and  with  others  of  which,  previously  ex- 
perienced, it  is  associated  by  perceived  likeness;  and  the 
implied  comparisons  of  sentient  states  are  impossible  unless 
the  correlative  nervous  changes  are  put  in  connexion  at  one 
place.  It  does  not  follow,  as  it  at  first  seems  to 

do,  that  feelings  are  never  located  in  the  inferior  nervous 
centres.  On  the  contrary,  it  may  well  be  that  in  lower 
types  the  homologues  of  these  inferior  centres  are  the  seats 
of  consciousness.  The  true  implication  is  that  in  any  case 
the  seat  of  consciousness  is  that  nervous  centre  to  which, 
mediately  or  immediately,  the  most  heterogeneous  impres- 
sions are  brought;  and  it  is  not  improbable  that  in  the 
course  of  nervous  evolution,  centres  that  were  once  the 
highest  are  supplanted  by  others  in  which  co-ordination  is 
carried  a  stage  further,  and  which  thereupon  become  the 
places  of  feeling,  while  the  centres  before  predominant 
become  automatic. 

Quite  congruous  with  this  conception  is  the  above-named 
fact,  that  certain  nervous  changes  which  have  subjective 
sides  early  in  life  cease  to  have  them  later  in  life.  Many 
acts  performed  by  the  child  slowly  and  consciously,  the 
adult  performs  rapidly  and  unconsciously.  Every  step 
taken  during  the  first  efforts  to  walk  has  its  accompanying 


106  THE  DATA  OF  PSYCHOLOGY. 

distinct  feelings;  but  eventually,  the  successive  steps  are 
made  while  consciousness  is  wholly  or  almost  wholly  occu- 
pied with  other  feelings.  Still  better  is  the  illustration 
furnished  by  speech.  Each  muscular  adjustment  of  the 
vocal  organs  and  each  articulate  sound  made,  have,  in 
childhood,  concomitant  sentient  states  that  are  vivid,  and, 
for  the  moment,  all-absorbing.  Gradually,  however,  these 
become  less  dominant  in  consciousness;  until  at  maturity 
there  is  entire  oblivion  of  the  one,  and  sometimes  partial  ob- 
livion of  the  other:  witness  the  not  unfrequent  verbal  mis- 
takes unconsciously  made  in  the  heat  of  discussion.  Now 
facts  of  this  kind,  countless  in  number  and  of  many  varieties, 
are  explicable  if  we  regard  feelings  as  the  subjective  sides  of 
such  nervous  changes  only,  as  are  brought  to  the  general  cen- 
tre of  nervous  connections.  When  we  remember  that 
early  in  life  each  inferior  ganglion,  or  cluster  of  co- 
operating inferior  ganglia,  is  imperfectly  organized,  and  the 
connections  among  its  fibres  incomplete;  we  shall  see  that 
if  there  comes  to  it  a  disturbance,  the  gush  of  molecular 
motion  liberated,  not  having  in  the  incompletely-connected 
commissural  and  efferent  fibres,  adequate  channels  of 
escape,  will  part  of  it  escape  along  a  centripetal  fibre  to 
a  higher  centre,  so  awakening  a  feeling.  And  it  will  mani- 
festly happen  that  the  approach  to  automatic  action  of  the 
lower  centre,  will  be  an  approach  to  a  state  in  which 
the  liberated  molecular  motion,  having  in  the  efferent  fibres 
fully-opened  channels  of  emission,  will  little  or  none  of 
it  be  forced  into  centripetal  fibres,  and  will  so  awaken  little 
or  no  feeling.  It  is  a  corollary  from  this  interpretation, 
that  all  gradations  will  exist  between  wholly  unconscious 
nervous  actions  and  wholly  conscious  ones;  since  there  will 
be  all  gradations  in  the  relative  amounts  of  the  disturb- 
ances which  take  their  courses  along  centripetal  fibres.  It 
obviously  follows,  too,  that  in  adult  life  a  nervous  action 
may  or  may  not  have  an  identifiable  subjective  aspect, 
according  as  it  is  strong  or  weak;    since,  if  there  comes 


-SISTHO-PHYSIOLOGY.  107 

to  a  finished  ganglion  constructed  as  described,  a  feeble 
disturbance,  the  whole  of  the  small  quantity  of  molecular 
motion  liberated  may  be  drafted  off  by  the  efferent  fibres; 
whereas,  if  the  disturbance  is  great,  the  disengaged 
molecular  motion,  being  more  than  can  find  its  way  along 
the  efferent  fibres,  will  some  of  it  take  a  centripetal  course 
and  cause  a  subjective  change. 

§  44.  A  kindred  aspect  of  this  correlation  presents  itself 
when  we  contemplate  feeling  as  occupying  time.  A  sub- 
jective state  becomes  recognizable  as  such,  only  when  it  has 
an  appreciable  duration:  it  must  fill  some  space  in  the 
series  of  states,  otherwise  it  is  not  known  as  present.  This 
general  truth  harmonizes  with  a  general  truth  before 
pointed  out  respecting  nervous  action,  as  well  as  with  the 
above  interpretation. 

The  observed  fact  that  time  is  taken  in  the  transit  of  a 
nerve- wave,  is  not  to  the  point;  for  this  transit  has  no 
concomitant  subjective  state.  But  the  inferred  fact  that' 
the  change  set  up  in  a  nerve-centre  must  take  time,  and 
a  more  considerable  time  (§  35),  is  relevant;  for  what  is 
objectively  a  change  in  a  superior  nerve-centre  is  subjectively 
a  feeling,  and  the  duration  of  it  under  the  one  aspect 
measures  the  duration  of  it  under  the  other. 

That  feeling  persists  after  the  force  arousing  it  ceases,  is 
not  proved  by  the  lengthened  sensation  produced  by  a 
moderate  blow  on  the  skin,  or  by  that  which  follows  dip- 
ping the  hand  into  hot-water,  or  by  those  which  the  palate 
and  the  nostrils  experience  from  pungent  substances  mo- 
mentarily applied;  for  though  in  such  cases  the  external 
action  of  the  exciting  agency  is  brief,  the  local  changes  it 
sets  up,  lasting  some  time,  continue  for  some  time  to  dis- 
turb the  local  nerve-fibres.  But  good  evidence  is  supplied 
by  impressions  on  the  retina.  To  quote  the  words  of 
Professor  Huxley: — "  A  flash  of  lightning  is,  practically, 
instantaneous,  but  the  sensation  of  light  produced  by  that 


X08  THE  DATA  OP  PSYCHOLOGY. 

flash  endures  for  an  appreciable  period.  It  is  found,  in 
fact,  that  a  luminous  impression  lasts  for  about  one-eighth 
of  a  second;  whence  it  follows,  that  if  any  two  luminous 
impressions  are  separated  by  a  less  interval,  they  are  not 
distinguished  from  one  another.  For  this  reason  a 
'  Catherine-wheel,'  or  a  lighted  stick  turned  round  very 
rapidly  by  the  hand,  appears  as  a  circle  of  fire;  and  the 
spokes  of  a  coach-wheel  at  speed  are  not  separately  visible, 
but  only  appear  as  a  sort  of  opacity,  or  film,  within  the  tire 
of  the  wheel." 

As  above  said,  this  general  truth  that  feeling  implies 
time,  harmonizes  with  the  interpretation  given  in  the  pre- 
ceding section;  and  supplies  a  further  elucidation  of  the 
relation  between  conscious  and  unconscious  nervous  action. 
For  manifestly,  in  proportion  as  nervous  co-ordinations 
become  more  automatic  they  become  more  rapid;  and 
for  this  reason  also,  cease  to  present  such  conspicuous 
subjective  aspects.  Returning  to  the  inferior  ganglion, 
or  cluster  of  co-operating  ganglia,  above  described,  it 
will  be  obvious  that  a  state  in  which  the  local  or- 
ganization is  incomplete,  and  the  various  afferent  and 
commissural  fibres  not  brought  into  definite  relations  with 
vesicles,  and  through  them  with  efferent  fibres,  must  be 
a  state  in  which  the  molecular  motion  liberated  by  an  in- 
coming shock  of  change,  will  pass  through  the  imperfectly 
differentiated  structure  with  comparative  slowness;  and 
there  will  therefore  be  an  appreciable  time  during  which 
centripetal  fibres  may  receive  disturbance.  But  as  fast  as 
the  local  connections  of  fibres  and  cells  become  complete, 
the  gush  of  molecular  motion,  following  the  completely- 
formed  channels,  will  escape  rapidly ;  and  the  period  during 
which  excitement  of  the  centripetal  fibres  may  take  place 
will  be  abridged.  The  concomitant  subjective  state  will 
therefore  be  rendered  shorter  by  the  same  change  that 
renders  it  feebler. 


^STHO-PHYSIOLOGY.  109 

§  45.  The  fact  that  each  feeling  lasts  an  appreciable  timd, 
introduces  us  to  the  allied  fact  that  each  feeling  produces 
a  greater  or  less  incapacity  for  a  similar  feeling,  which  also 
lasts  an  appreciable  time.  This,  too,  is  the  subjective  side 
of  a  phenomenon  before  noticed  under  its  objective  side 
(§36).  For  as  the  duration  of  a  feeling  answers  to  the 
duration  of  the  molecular  disintegration  in  a  disturbed 
nerve-centre;  so  the  subsequent  interval  of  diminished 
ability  to  feel,  answers  to  the  interval  during  which  the 
disintegrated  nerve-centre  is  re-integrating  itself.  Let  us 
observe  how  among  sensations  of  all  kinds  we  may  trace 
conformity  to  this  law. 

An  illustration  is  supplied  by  the  sense  of  touch.  If  the 
fingers  be  repeatedly  swept  rapidly  over  something  covered 
by  numerous  small  prominences,  as  the  papillated  surface 
of  an  ordinary  counterpane,  a  peculiar  feeling  of  numbness 
in  them  results:  the  objects  touched  the  moment  after  seem 
smoother  than  usual ;  implying  that  the  small  irregularities 
on  them  produce  less  vivid  impressions.  That 

the  sensation  of  muscular  tension  undergoes  a  variation 
similarly  caused,  everyone  knows.  After  carrying  a  very 
heavy  body  in  the  hand  for  some  time,  a  small  body  held 
in  the  same  hand  appears  to  have  lost  its  weight;  showing 
that  the  nerve-centre  which  is  the  seat  of  the  sensation  has 
been,  for  the  moment,  rendered  obtuse.  How  the 

gustatory  faculty  is  exhausted  for  a  time  by  a  strong  taste, 
daily  experience  teaches.  When  sugar  or  honey  has  just 
been  eaten,  things  that  are  but  slightly  sweetened  seem  to 
have  no  sweetness.  While  the  palate  is  still  hot  with 
a  curry,  an  unflavoured  dish  seems  insipid;  and  a 
glass  of  liqueur  is  fatal  to  the  appreciation  of  a  choice 
wine.  Even  more  marked  is  that  incapacity  of 

the  sense  of  smell  caused  in  like  manner.  The  intensity 
of  the  pleasurable  feeling  given  by  a  rose  held  to  the 
nostrils,  rapidly  diminishes;  and  when  the  sniffs  have  been 
continued  for  some  time,  scarcely  any  scent  can  be  per- 


110  THE  DATA  OF  PSYCHOLOaY. 

ceived.  A  few  minutes'  rest  partially  restores  tlie  impressi- 
bility; but  a  long  interval  must  elapse  before  the  odour 
is  enjoyed  as  keenly  as  at  first.  This  quick  exhaustion, 
producing  in  such  cases  some  disappointment,  has  its 
correlative  advantage  when  the  smells  are  disagreeable. 
Very  soon  these  become  much  less  perceptible;  and  to 
those  living  in  it  a  stench  gives  scarcely  any  annoy- 
ance. The  feelings  generated  by  sonorous  vibra- 
tions rarely  show  us  this  variation  in  a  marked  degree; 
being,  as  they  commonly  are,  too  short  to  leave  much 
nervous  prostration.  A  strong  taste,  or  odour,  or  sensation 
of  muscular  tension,  is  due  to  an  action  on  the  nerves  that 
is  maintained  for  a  considerable  time;  but  the  actions  to 
which  are  due  those  loud  sounds  required  to  cause  tempo- 
rary unimpressibiUty,  are  mostly  very  brief.  Illustrations 
are  to  be  expected  only  in  special  cases;  and  in  these  we 
find  them.  The  bang  of  a  cannon  is  described  as  deafening 
by  those  who  are  close  to  the  cannon  when  it  is  fired,  be- 
cause they  are  rendered  for  a  time  partially  deaf  to  ordi- 
nary sounds.  On  men  engaged  in  artillery-practice,  the 
repeated  explosions  entail  a  dulness  of  hearing  that  lasts 
for  hours;  and  this  dulness  of  hearing  becomes  per- 
manent in  those  who  are  permanently  occupied  in  such 
practice.  Numerous  and  very  conclusive  proofs 
are  supplied  by  the  feelings  we  receive  from  light.  There 
are  two  classes  of  them :  those  showing  us  a  variable  sensi- 
bility to  light  in  general,  as  contrasted  with  darkness;  and 
those  showing  us  a  variable  sensibility  to  each  kind  of  light 
— each  colour.  Under  the  one  head  the  reader  may  first  be 
reminded  of  the  experience  that  on  going  out  of  broad  sun- 
shine into  a  dimly-lighted  place,  it  is  impossible  to  discern 
the  surrounding  objects:  only  after  a  time  do  they  become 
faintly  visible,  and  a  considerable  interval  elapses  before  they 
are  seen  with  clearness.  Disabilities  similarly  caused  are  dis- 
closed, when,  instead  of  acting  on  the  retinae  as  wholes,  we 
act  differently  on  their  different  parts.     Hence  what  are 


^STHO-PHYSIOLOGY.  IH 

called  negative  images.  If,  after  gazing  for  some  moments 
at  an  object  presenting  strong  contrasts  of  light  and  dark 
parts,  the  eyes  are  turned  towards  a  shaded  space,  containing 
nothing  conspicuous,  there  will  be  perceived  a  transient 
image  of  the  object,  in  which  the  light  and  dark  parts  are  re- 
versed. The  interpretation  of  this  fact  is  that  those  por- 
tions of  each  retina  on  which  strong  light  had  fallen,  to- 
gether with  the  answering  portions  of  the  optic  centres, 
having  undergone  the  most  change  with  correspond- 
ing production  of  the  most  feeling,  are  the  next  in- 
stant less  capable  of  undergoing  change  and  evolving 
feeling  than  the  portions  on  which  feeble  light  had  fallen; 
and  hence,  when  they  are  together  exposed  to  the  same 
feeble  light,  the  unexhausted  parts  appreciate  it  more  than 
the  exhausted  parts,  and  a  negative  image  results.  The 
cases  of  the  second  class  are  the  well-known  phenomena  of 
subjective  complementary  colours.  After  looking  intently 
at  a  surface  of  bright  red,  an  adjacent  surface  of  white 
seems  to  have  a  greenish  tint.  The  explanation  is  obvious. 
Those  nervous  elements  changed  by  the  rays  which  produce 
in  us  the  sensation  of  redness,  having  been  partially  inca- 
pacitated, the  red  rays  contained  in  the  white  light  cause 
less  of  their  appropriate  effect  than  usual;  while  the  blue 
and  yellow  rays  causing  their  usual  effects,  and  therefore 
relatively-predominant  effects,  a  sensation  of  greenness 
arises. 

This  decrease  in  the  susceptibility  to  a  feeling  of  any 
kind,  which  immediately  follows  a  feeling  of  that  kind, 
is  not  a  constant  decrease.  It  is  a  decrease  that  varies 
greatly  in  degree;  and  from  its  variation  we  may  derive 
further  instructive  evidence.  Other  things  equal,  it  is  small 
or  great  according  to  the  great  or  small  constitutional 
vigour.  One  of  these  disabilities  lasts  for  a  scarcely 
appreciable  time  when  the  vital  activities  are  high; 
and  lasts  for  a  time  that  becomes  longer  and  longer 
as  the    vital  activities  flag.     Abundant  proof  of  this  is 


112  THE  DATA  OF  PSYCHOLOGY. 

furnished  by  the  negative  images  just  described.  In 
youth  these  are  scarcely  if  at  all  to  be  observed:  only 
when  an  extremely-vivid  retinal  impression  has  been  pro- 
duced, as  by  looking  at  the  Sun,  is  the  negative  image 
perceptible.  But  in  middle  life  and  afterwards,  especially 
in  debilitated  persons,  negative  images  of  ordinary  objects 
are  very  commonly  perceived,  and  often  have  considerable 
durations.*  Feeling  being  the  subjective  correlate  of  that 
which  we  know  objectively  as  nervous  action,  these  facts 
are  obvious  corollaries  from  facts  set  down  in  the  last 
chapter.  We  there  saw  that  the  excitement  of  a  nerve- 
centre  involves  waste;  and  that  restoration  of  the  nerve- 
centre  to  a  state  of  equal  susceptibility  can  be  effected 
only  by  repair.  Hence  the  return  of  fitness  for  what  is 
objectively  stimulation  and  subjectively  feeling,  will  vary 
in  quickness  according  to  the  rate  of  repair.  When  the 
blood  is  rich  and  rapidly  circulated,  the  partial  disability 
will  be  but  momentary;  and,  unless  the  sensation  has  been 
intense,  will  be  inappreciable.  But  along  with  failing  nutri- 
tion of  the  tissues,  the  disability  will  become  marked  and 
its  duration  longer.  In  further  illustration  of  this,  I  may 
name  the  fact  that  negative  images  are  most  conspicuous 
on  awaking  in  the  morning,  when  the  circulation  is 
slow.  The  sense  of  hearing  yields  parallel  evi- 

dence;   though  evidence  of  which  the  parallelism  is  not 

*  This  change  comes  on  so  gradually  that  very  few  remark  it ;  and  the 
usual  supposition  is  that  negative  images  are  much  the  same  at  all  ages  and 
in  all  persons.  I  am  able,  however,  to  give  personal  testimony  to  the  con- 
trary. When  about  twenty  years  of  age,  my  attention  was  drawn  by  my 
fnther  to  a  case  in  which  the  circumstances  were  favourable  for  perceiving 
the  negative  image,  and  in  which  he  perceived  it  clearly.  To  me  it  was 
invisible ;  and  I  well  remember  his  remark,  that  I  should  beprin  to  see 
such  images  as  I  became  older.  He  was  right.  I  now  see  them  distinctly ; 
and,  moreover,  I  observe  that  they  are  most  distinct  at  times  of  least 
vigour.  It  is  worth  while  inquiring  how  far  this  change  affects  the 
appreciation  of  the  chromatic  harmonies.  It  seems  inferable  that  the 
harmonies  of  complementary  colours  become  more  perceptible  as  life  ad- 
vances. 


iESTHO-PHYSIOLOGY.  113 

immediately  obvious.  Persons  on  whom  old  age  or  debility 
brings  deafness,  frequently  describe  themselves  as  having 
no  difficulty  in  hearing  sounds,  but  as  being  unable  to 
disentangle  and  identify  words  when  they  are  indistinctly 
or  rapidly  uttered.  Supposing  that  in  such  cases  the 
nervous  structures  concerned  suffer  from  faulty  nutrition, 
we  have  an  explanation  of  this  peculiarity.  For  if  each  of 
the  successive  sounds  entails  waste  of  the  auditory  centres, 
and  leaves  them  less  sensitive  to  like  sounds,  it  must  fol- 
low that,  when  re-integration  is  slow,  the  like  sounds  im- 
mediately afterwards  received  will  produce  less  than  their 
due  amounts  of  sensation.  These  defects  of  sensation  will 
show  themselves  most  in  a  comparative  deadness  to  those 
delicate  consonantal  modifications  by  which  words  are 
mainly  distinguished  from  one  another — the  utterances 
listened  to  will  seem  a  series  of  vowel-sounds  joined  by 
blurred  consonants.  Hence  the  reason  why  persons  thus 
affected,  ask  those  who  address  them  to  articulate  slowly 
and  clearly.  The  confusion  of  impressions  produced  by 
rapid  speech  on  auditory  centres  thus  debilitated,  may  be 
conceived  by  supposing  debilitated  optic  centres  to  be 
similarly  treated.  If  a  person  in  whom  the  negative 
images  are  strong,  has  a  series  of  objects  passed  before 
his  eyes  so  fast  that  he  can  have  only  a  momentary  glance 
at  each  (to  parallel  the  momentary  opportunity  which  the 
ears  have  of  identifying  each  successive  articulation) ;  then 
it  will  manifestly  happen  that  the  negative  image  of  each 
object  will  interfere  with,  and  confuse,  the  positive  image 
of  the  next;  and  such  a  person  will  therefore  not  identify 
the  successive  objects  so  readily  as  one  whose  optic  centres 
are  repaired  with  normal  speed.  As  confirming  the  be- 
lief that  this  defect  of  hearing  is  so  caused,  I  may  add 
that  it  frequently  co-exists  with  the  defect  of  vision  to 
which  I  have  compared  it;  and  also  that  the  one,  like  the 
other,  is  most  marked  early  in  the  day,  and  is  diminished 
by  whatever  invigorates  the  circulation. 


114  THE  DATA  OF  PSYCHOLOGY. 

§  46.  Another  class  of  correlations  demands  a  passing 
notice.  Up  to  this  point,  the  feelings  considered  have  been 
subjective  aspects  of  those  changes  which  objectively  are 
nervous  stimulations.  We  have  now  to  consider  certain 
other  feelings  which  are  the  inner  faces  of  what  on  their 
outer  faces  are  nervous  discharges.  Having  traced  pretty 
fully  the  concomitance  of  sentient  states  and  redjpio-motor 
acts,  it  will  suffice  to  trace  briefly  the  concomitance  of 
sentient  states  and  dirigo-motor  acts. 

Certain  inferior  dirigo-motor  acts  are  unconscious;  but 
omitting  these,  the  law  is  that  with  each  muscular  contrac- 
tion there  goes  a  sensation  more  or  less  definite.  This  is  not 
a  sensation  indirectly  produced  through  the  nerves  proceed- 
ing inwards  from  the  skin,  some  of  which  are  nearly  always 
disturbed  by  each  bodily  motion;  but  it  is  a  sensation  directly 
produced,  either  by  the  discharge  itself  or  by  the  state  of  the 
muscle  or  muscles  excited.  It  is  most  clearly  distinguished 
when,  without  touching  anything  and  without  moving,  a 
leg  or  arm  is  held  out  at  right  angles  to  the  body. 

Vague  as  are  feelings  of  this  class  in  comparison  with 
most  feelings  accompanying  nervous  stimulations,  and  much 
less  numerous  as  are  the  varieties  of  quality  among  them, 
they  are  nevertheless  so  far  definite  and  different  that  we 
can,  to  a  certain  extent,  recognize  the  separate  feeling  ber 
longing  to  each  separate  contraction.  We  are  aware  with- 
out looking  at  it,  and  without  touching  anything  with  it, 
which  finger  has  been  bent  by  the  discharge  sent  to  its 
flexor  muscles;  and,  by  the  particular  combination  of  feel- 
ings accompanying  the  act,  the  placing  of  a  limb  in  a  given 
attitude  is  present  to  consciousness  without  aid  from  the 
eyes  or  hands.  I  say  we  can  to  a  certain  extent  recognize 
the  changes  we  thus  set  up ;  because  the  differences  among 
the  sensations  of  muscular  tension  soon  lose  much  of  their 
distinctness.  It  is  a  curious  fact  that  when  a  limb  has  been 
held  for  some  time  in  any  position,  especially  if  the  position 
is  one  involving  but  little  strain,  the  subjective  state  asso- 


^STHO-PHYSIOLOGY.  115 

ciated  with  the  nervous  discharge  to  its  muscles,  becomes  so 
indefinite  that  the  attitude  of  the  limb  is  unknown,  if  there 
does  not  happen  to  be  a  recollection  of  it. 

Besides  the  connection  between  what  we  know  objectively 
as  a  particular  motor  act,  and  subjectively  as  a  particular 
feeling  of  muscular  tension,  there  is  a  connection  between 
the  accompanying  motor  excitement  propagated  throughout 
the  muscular  system,  and  a  certain  diffused  feeling  of  which 
it  is  the  seat.  How  along  with  each  special  nervous  discharge 
there  goes  a  general  nervous  discharge,  we  saw  in  the  last 
chapter;  and  here  we  recur  to  the  relation  only  to  observe 
that  there  is  a  parallel  relation  between  the  concomitant 
states  of  consciousness.  Thus  the  vivid  sensation  caused 
by  putting  the  foot  into  scalding  water,  does  not  lead  only 
to  the  muscular  contractions  and  muscular  feelings  which 
accompany  the  sudden  withdrawal  of  the  leg,  but  also  to 
contractions  of  countless  other  muscles  throughout  the 
body,  and  a  feeling  called  a  shock  or  start. 

!N^or  are  these  subjective  states,  special  and  general,  that 
accompany  special  and  general  discharges  to  the  muscles^ 
the  only  subjective  states  that  accompany  discharges.  As 
before  pointed  out,  the  vascular  system  and  the  alimentary 
system  receive  their  shares  of  each  discharge — very  appre- 
ciable when  it  is  intense,  and  probably  in  no  case  wanting; 
and  these,  too,  present  inner  aspects  to  consciousness.  Some- 
times, indeed,  the  feelings  that  go  along  with  discharges 
into  the  vaso-motor  and  sympathetic  nerves,  are  the  pre- 
dominant ones;  as  instance  the  thrill  diffused  through  the 
body  by  certain  acute  creaking  sounds  said  to  "  set  the 
teeth  on  edge ;  "  or  the  nausea  produced  by  particular  kinds 
of  disagreeable  odours. 

§  4Y.  Are  these  correlations  between  nervous  actions  and 
the  concomitant  feelings  quantitative?    Is  there  such  con- 
nection between  a  physical  change  in  the  nervous  system 
and  the  psychical  change  accompanying  it,  that  we  may 
9 


116  THE  DATA  OF  PSYCHOLOGY. 

regard  the  one  as  an  equivalent  of  the  other,  in  the  same 
sense  as  we  regard  so  much  heat  as  the  equivalent  of  so 
much  motion?  The  reader  will  perhaps  expect  an  affirma- 
tive answer;  but  if  an  affirmative  answer  is  to  be  given,  it 
must  be  given  in  a  greatly-qualified  form. 

On  remembering  that  many  nervous  actions  are  always 
unconscious;  on  also  remembering  that  various  objective 
states  of  the  nervous  system  which  have  associated  sub- 
jective states  early  in  life,  cease  to  have  them  later  in  life ; 
and  on  remembering,  further,  that  at  the  same  period  of 
life  a  change  set  up  in  an  afferent  nerve  may  cause  an 
appreciable  feeling,  or  may  not  cause  it,  according  as  the 
attention  is  free  or  occupied;  we  shall  see  that  the  con- 
nection between  feelings  and  nervous  changes  is  con- 
ditioned in  a  very  complex  way,  and  that  if  they 
are  quantitatively  related  it  can  be  only  within  the 
narrow  limits  implied  by  the  complex  conditions.  If  be- 
tween a  purely  voluntary  act  and  a  purely  automatic  act 
there  are  gradations — if,  at  the  one  extreme,  feeling  is  a 
conspicuous  accompaniment,  and,  at  the  other  extreme, 
ceases  to  be  an  accompaniment;  then,  clearly,  in  the  in- 
termediate phases  the  amount  of  feeling  must  bear  a  vary- 
ing ratio  to  the  amount  of  nervous  change  which  the  act 
implies.  Again,  if  we  assume  that  what  is 

present  to  consciousness  as  a  sensation  of  given  strength, 
is  the  correlate  of  a  proportionate  molecular  disturbance  in 
all  the  nervous  structures  concerned,  how  shall  we  interpret 
the  sensations  distinguished  as  subjective?  In  sundry  ab- 
normal states,  strong  feelings  of  cold  or  heat  are  felt 
throughout  the  body,  though  its  actual  temperature  has 
remained  unaltered.  As  in  any  case  of  this  kind  the  total 
nervous  change  cannot  have  been  the  same  as  if  the  skin 
had  fallen  or  risen  in  temperature  to  the  degree  ordinarily 
required  to  produce  the  feeling,  we  cannot  say  that  there 
18  a  quantitative  equivalence  between  the  amount  of  nervous 
change  and  the  amount  of  feeling.    The  disagreeable  smell 


^STHO-PHYSIOLOGY.  117 

which,  on  the  approach  of  a  fit,  the  epileptic  patient  fre- 
quently complains  of,  affords  a  yet  better  illustration. 
Here  the  outer  ends  of  the  afferent  nerves  being  undis- 
turbed, and  only  certain  central  structures  irritated,  the 
quantity  of  nervous  action  is  not  the  same  as  if  the  sensation 
had  been  generated  by  an  actual  smell.  More 

conspicuously  still  do  we  see  the  variability  of  this  rela- 
tion, when  we  compare  the  feelings  called  efforts  with  the 
discharges  and  muscular  strains  produced  by  them  under 
different  conditions.  If  the  psychical  force  known  as  effort 
were  transformable  into  a  constant  quantity  of  physical 
force,  then,  in  any  two  cases,  equal  efforts  should  produce 
equal  contractions.  But  they  do  not.  Great  exertion  in  a 
child  fails  to  evolve  from  its  motor  organs  the  dynamic 
effect  which  a  small  exertion  evolves  from  those  of  a 
man.  Any  one  who  is  fatigued  finds  that  an  intenser 
feeling  of  strain  is  requisite  to  generate  a  given  degree  of 
muscular  tension,  than  when  he  is  fresh.  And  those  pros- 
trated by  illness  show  us  that  immense  expenditures  of  feel- 
ing are  needed  to  perform  acts  which,  during  health,  need 
scarcely  appreciable  expenditures  of  feeling.  Doubtless 
these  differences  are  partly  due  to  differences  in  the 
muscles;  which,  when  undeveloped  or  when  wasted,  are 
excited  to  smaller  amounts  of  tension  by  equal  amounts  of 
discharge.  But  we  must  regard  them  as  partly  due  to  the 
imperfect  development,  or  the  worn  state,  of  the  interme- 
diate motor  centres  and  efferent  nerves,  in  which  a  given 
feeling  excites  a  smaller  molecular  disturbance  than  when 
they  are  finished  in  structure  and  in  complete  repair — a 
conclusion  enforced  by  the  familiar  experience  that  purely 
nervous  acts,  as  those  of  thought,  require  unusual  efforts 
when  the  brain  is  tired. 

This  variability  of  the  quantitative  relation  between 
nervous  actions  and  psychical  states,  is  equally  seen  when 
we  limit  our  comparisons  to  those  nervous  actions  and 
psychical  states  which  occur  in  the  same  individual  under 


118  THE  DATA  OF  PSYCHOLOGY. 

the  same  bodily  conditions.  To  show  that  unlike  but 
equally  intense  sensations  may  be  produced  by  peripheral 
disturbances  widely  unlike  in  their  amounts,  providing  they 
arise  in  different  external  sense-organs,  is  scarcely  possible 
without  comparing  the  amounts  of  the  incident  forces; 
and  this  we  cannot  properly  do,  since  we  are  here  confining 
our  attention  to  correlations  within  the  organism.  We  are 
similarly  debarred  from  going  at  length  into  the  quantita- 
tive contrasts  between  the  muscular  tensions  produced  by 
the  same  feeling  of  effort,  according  as  the  muscles  excited 
are  large  or  small;  for  we  cannot  well  establish  these  con- 
trasts without  measuring  the  muscular  tensions  by  the 
external  actions  they  are  equivalent  to.  There  is,  however, 
one  class  of  appropriate  cases — those  in  which  irritations 
arising  within  the  organism,  set  up  sensations  that  cause 
undirected  motor  discharges.  Violent  toothache,  for  ex- 
ample, is  due  to  waves  of  molecular  change  sent  through 
one  or  two  minute  afferent  nerve-fibres;  but  the  bodily 
contortions  show  us  that  the  feeling  so  produced,  sufiices  to 
send  waves  of  molecular  change  through  various  large 
bundles  of  efferent  nerve-fibres,  and  to  contract  numerous 
muscles  with  much  force.  To  which  of  these  disturbances, 
centripetal  or  centrifugal,  is  the  feeling  equivalent?  We 
cannot  say  to  both,  for  one  is  many  times  the  other  in 
amount;  and  we  have  no  reason  to  say  that  it  is  equivalent 
to  one  rather  than  to  the  other :  the  rational  inference  being 
that  it  is  not  equivalent  to  either. 

To  understand  the  real  relations  between  objective  and 
subjective  changes  in  the  nervous  system,  we  need  but  to 
recall  certain  of  the  conclusions  reached  in  preceding 
chapters.  The  essential  principle  of  nervous  organiza- 
tion we  have  seen  to  be  that  the  small  amounts  of  mo- 
tion received,  liberate  larger  amounts,  and  these  again 
still  larger  amounts.  A  disturbance  in  the  end  of  an 
'afferent  nerve  is  multiplied  as  it  traverses  the  nerve,  and 
the  degree  of  multiplication  varies  with  the  length  of  the 


-S:STHO-PHYSIOLOGY.  119 

nerve;  it  is  mucli  more  multiplied  in  the  first  ganglion; 
reached,  and  increases  further  in  traversing  the  centripetal . 
nerve;  it  is  again  multiplied  in  the  superior  centre,  to  be 
afterwards  augmented  in  its  subsequent  centrifugal  course; 
and  it  is  once  more  multiplied,  probably  in  a  far  greater 
degree,  in  the  contractile  substance  of  the  excited  muscles. 
Hence  the  accompanying  feeling,  which  is  the  subjective 
aspect  of  this  disturbance  at  one  of  its  intermediate  stages, 
can  be  a  quantitative  equivalent  neither  of  the  initial  nervous 
change  nor  of  the  terminal  nervous  change.  Moreover, . 
since  the  multiplication  varies  in  degree,  being  much  greater 
in  the  organs  of  the  higher  senses  than  in  those  of  the  lower, 
it  follows  that  the  ratio  between  the  amount  of  feeling  and 
the  amount  of  initial  change  is  far  from  constant;  and  the 
evidence  clearly  indicates  a  like  inconstancy  of  the  ratio 
tetween  the  amount  of  feeling  and  the  amount  of  terminal 
change,  according  as  one  or  other  muscle  or  set  of  muscles, 
is  made  to  act. 

How  then  can  there  be  any  quantitative  relation,  it  will 
be  asked.  If  there  is  no  equivalence  between  a  disturbance 
set  up  at  the  periphery  and  the  produced  feeling,  and  no 
equivalence  between  the  produced  feeling  and  the  motor 
discharge  that  follows — if  the  feeling  does  not  even  bear 
the  same  ratio  to  either  the  initial  or  the  terminal  nervous 
change  in  different  cases;  what  quantitative  relation  can 
there  be?  The  reply  is  simple.  There  is  a  quantitative 
relation  between  nervous  change  and  feeling  when  all  other 
things  remain  the  same;  and  there  is  a  quantitative  relation 
between  feeling  and  resulting  contraction  when  all  other 
things  remain  the  same.  Supposing  every  condition  to 
continue  unaltered,  then  the  stimulus  conveyed  through 
a  given  nerve  to  a  given  centre,  will  evoke  a  feeling  that 
increases  and  decreases  in  something  like  the  same  pro- 
portion as  the  stimulus  increases  and  decreases;  and,  sup- 
posing a  given  muscle  to  be  contracted,  then  the  amount 
of  its  contraction  will  bear  a  tolerably  constant  ratio  to 


120  THE  DATA   OF  PSYCHOLOGY. 

the  feeling  of  effort  that  accompanies  the  contraction  of 
it.  The  nature  of  these  correlations  may  best  be  expressed 
by  numbers.  If,  coming  through  a  given  afferent  nerve, 
a  disturbance  represented  by  1  generates  a  feeling  repre- 
sented by  5,  then  disturbance  2  will  generate  feeling  10, 
and  disturbance  5  feeling  25;  and  if,  acting  through  a 
given  efferent  nerve,  feeling  5  results  in  muscular  tension 
60,  feeling  10  will  result  in  muscular  tension  120.  But  to 
complete  this  numerical  expression  of  the  facts  we  must 
suppose  these  ratios  to  vary  with  every  set  of  afferwit 
nerves  and  every  set  of  efferent  nerves.  If  we  say  that 
1  to  5  represents  the  ratio  of  disturbance  to  feeling  in  the 
sense  of  touch,  then  to  represent  it  in  the  sense  of  hearing 
will  need,  say,  1  to  100,  and  in  the  sense  of  sight  perhaps 
1  to  1,000;  and  similarly  with  the  ratios  throughout  the 
motor  apparatus,  according  as  the  muscles  are  large  or 
small. 

In  brief,  then,  the  quantitative  correlation  of  feeling 
and  nervous  change,  holds  true  only  within  narrow  limits. 
We  have  good  reason  to  conclude  that  at  the  particular 
place  in  a  superior  nervous  centre  where,  in  some  mys- 
terious way,  an  objective  change  or  nervous  action  causes  a 
subjective  change  or  feeling,  there  exists  a  quantitative 
equivalence  between  the  two:  the  amount  of  sensation  is 
proportionate  to  the  amount  of  molecular  transformation 
that  takes  place  in  the  vesicular  substance  affected.  But 
there  is  no  fixed,  or  even  approximate,  quantitative  relation 
between  this  amount  of  molecular  transformation  in  the 
sentient  centre,  and  the  peripheral  disturbance  originally 
causing  it,  or  the  disturbance  of  the  motor  apparatus  which 
it  may  eventually  cause. 

§  48.  The  feelings  called  sensations  have  alone  been  con- 
sidered thus  far;  leaving  out  of  view  the  feelings  dis- 
tinguished as  emotions.  Much  less  definite  as  they  are, 
and  not  capable  of  being  made  at  will  the  objects  of  ob- 


^STHO-PHYSIOLOGY.  121 

servation  and  experiment,  the  emotions  are  more  difficult 
to  deal  with.  But  having  discerned  certain  general  laws 
to  which  the  simpler  feelings  conform,  we  may  now  ask 
whether,  so  far  as  we  can  see,  they  are  conformed  to 
by  the  more  complex  feelings.  We  shall  find  that 
they  are. 

The  conditions  essential  to  the  one  are  essential  to  the 
other.  Emotions,  like  sensations,  may  be  increased  or 
decreased  in  intensity  by  altering  either  the  quantity  or 
the  quality  of  the  blood.  That  general  abundance  of 
blood  is  a  cause  of  emotional  exaltation,  though  tolerably 
certain,  is  not  easily  proved;  but  there  is  sufficient  evidence 
of  the  converse  fact  that,  other  things  equal,  depletion  is  a 
cause  of  apathy.  The  effect  of  local  abundance  of  blood  is 
undoubted:  there  is  no  question  that,  within  limits,  the 
amount  of  emotion  varies  as  the  amount  of  blood  supplied 
to  the  great  nervous  centres.  That  nervous  stimulants  in- 
tensify the  emotions,  or,  as  we  say,  raise  the  spirits,  is 
even  more  manifest  than  that  they  make  the  sensations 
keener.  And  it  is  a  familiar  truth  that  sedatives  diminish 
what  is  distinguished  as  moral  pain,  in  the  same  way  that 
they  diminish  pain  arising  in  the  trunk  or  limbs. 

That  a  feeling  lasts  an  appreciable  time,  is  no  less 
true  of  an  emotion  than  of  a  sensation:  indeed  the  per- 
sistence is  relatively  conspicuous.  The  state  of  conscious- 
ness produced  by  a  flash  of  lightning,  is  so  brief  as  to 
seem  instantaneous:  only  by  the  help  of  artificial  tests  are 
sensations  of  this  kind  found  to  have  measurable  durations. 
But  no  such  tests  are  needed  to  prove  that  emotions  con- 
tinue through  appreciable  periods.  Even  a  simple  emotion, 
as  of  anger  or  fear,  does  not  reach  its  full  strength  the 
moment  the  cause  presents  itself;  and  after  the  cause  is 
removed  it  takes  some  time  to  die  away.  When  hereafter 
we  deal  with  the  origin  of  emotions,  and  recognize  the 
fact  that  they  are  of  far  more  involved  natures  than  sensa- 
tions, and  imply  the  co-operation  of  extremely  intricate 


122  THE  DATA  OP  PSYCHOLOGY. 

nervous  structures,  we  shall  understand  how  this  greater 
duration  is  necessitated. 

That  an  emotion,  like  a  sensation,  leaves  behind  it  a  tem- 
porary incapacity,  is  also  true ;  and  as  the  emotion  produced 
by  a  momentary  cause  lasts  longer  than  a  sensation  pro- 
duced by  a  momentary  cause,  so  does  the  partial  incapacity 
for  a  like  emotion  last  longer  than  the  partial  incapacity 
for  a  like  sensation.  Passions  of  all  kinds  come  in  gushes 
or  bursts.  That  they  often  continue  for  hours  and  days, 
is  true;  but  they  are  never  uniform  throughout  hours 
and  days.  Be  it  in  grief,  or  joy,  or  tenderness,  there  is 
always  a  succession  of  rises  and  falls  of  intensity — a 
paroxysm  of  violent  feeling  with  an  interval  of  feeling  less 
violent,  followed  by  another  paroxysm.  And  then,  after  a 
succession  of  these  comparatively-quick  alternations,  there 
comes  a  calm — a  period  during  which  the  waves  of 
emotion  are  feebler:  succeeded,  it  may  be,  by  another 
series  of  stronger  waves.  As  in  the  case  of  the  sensations  so 
in  the  case  of  the  emotions,  this  follows  from  the  fact  that 
what  is  objectively  a  nervous  action  and  subjectively  a 
feeling,  involves  waste  of  the  nervous  structures  concerned. 
The  centres  which  are  the  seats  of  emotions  undergo  dis- 
integration in  the  genesis  of  emotions;  and,  other  things 
remaining  equal,  thereupon  become  less  capable  of  genera- 
ting emotions  until  they  are  re-integrated.  I  say,  other 
things  remaining  equal,  because  the  rise  of  an  emotion 
brings  blood  to  the  parts  implicated,  and  so  long  as  the 
afflux  is  increasing  the  intensity  of  the  emotion  may  in- 
crease, notwithstanding  the  waste  that  has  taken  place; 
but  the  several  conditions  on  which  activity  depends  having 
become  constant,  a  diminished  capacity  for  emotion  inevit- 
ably follows  each  gush  of  emotion. 

That  daily  rises  and  falls  of  strength,  consequent 
on  daily  periodicities  of  waste  and  repair,  occur  in  the 
emotions  as  in  the  sensations,  is  also  tolerably  mani- 
fest.   Cultivated  people,  mostly  leading  lives  that  exercise 


iESTHO-PHYSIOLOGY.  123 

their  brains  too  much  and  their  muscles  too  little,  and 
placed  in  social  conditions  that  commonly  bring  the 
strongest  excitements  towards  the  close  of  the  day,  are 
subject  to  an  abnormal  periodicity.  But  those  whose  lives 
conform  best  to  the  laws  of  health,  exhibit  early  in  the 
day  a  general  joyousness  and  emotional  vivacity  greater 
than  they  do  towards  its  close,  when  approaching  sleepi- 
ness is  shown  by  a  flagging  interest  in  the  things  and 
actions  around. 

These  complex  feelings  that  are  centrally  initiated  are 
also  like  the  simple  feelings  that  are  peripherally  initiated, 
in  having  general  discharges  as  well  as  special  discharges: 
indeed  their  general  discharges  are  the  more  conspicuous 
of  the  two.  A  sensation  is  often  visibly  followed  only  by 
local  movement :  unless  very  strong  its  effect  on  the  organ- 
ism as  a  whole  is  unobtrusive.  But*  an  emotion,  besides 
the  more  obvious  changes  it  works  in  the  muscles  of  the 
face,  habitually  works  changes,  external  and  internal, 
throughout  the  body  at  large.  The  respiration,  the  circula- 
tion, the  digestion,  as  well  as  the  attitudes  and  movements, 
are  influenced  by  it  even  when  moderate;  and  everyone 
knows  how  strong  passions,  pleasurable  or  painful,  pro- 
foundly disturb  the  whole  system. 

§49.  Nothing  has  yet  been  said  about  the  most  con- 
spicuous and  most  important  distinction  existing  among 
the  feelings.  Every  feeling,  besides  its  minor  variations  of 
intensity,  exists  under  two  strongly-contrasted  degrees  of 
intensity.  There  is  a  vivid  form  of  it  which  we  call  an 
actual  feeling,  and  there  is  a  faint  form  of  it  which  we  call 
an  ideal  feeling.  What  is  the  nature  of  this  difference  as 
interpreted  from  our  present  stand-point? 

When  studying  nerve-structure,  we  saw  that,  in  addition 
to  connections  formed  by  grey  matter  between  the  central 
ends  of  afferent  and  efferent  nerves,  these  have  connec- 
tions   with    centripetal    and    commissural    nerves,    which 


124  THE  DATA  OP  PSYCHOLOGY. 

are  again  connected  with  more  distant  nerves.  And 
when  studying  nerve-function,  we  saw  that  a  disturb- 
ance set  up  by  an  afferent  nerve  in  its  ganglion,  does 
not  affect  exclusively  the  efferent  nerve,  but  that  part 
of  it,  conveyed  through  centripetal  and  commissural 
nerves,  affects  other  centres,  and  these  again  others,  until 
it  has  reverberated  throughout  the  entire  nervous  system. 
What  follows?  These  reverberations  are  feeble  disturb- 
ances. And  every  centre,  liable  as  it  is  to  be  strongly 
disturbed  through  its  afferent  or  centripetal  nerve,  is  liable 
also  to  be  feebly  disturbed  by  these  reverberations  arriving 
through  other  nerves.  What  then  must  happen  with  each 
of  the  libero-nwtor  elements  composing  those  higher  centres 
in  which  nervous  changes  become  changes  of  consciousness? 
When  it  is  affected  through  the  direct  and  fully-opened  route, 
by  that  peripheral  impression  to  which  it  stands  organically 
related,  it  evolves  much  molecular  motion,  becomes  an  active 
propagator  of  disturbances  throughout  the  nervous  system, 
and  is  the  seat  of  what  we  call  a  real  feeling;  but  when  it 
is  affected  by  these  secondary  waves  diffused  from  other 
strongly  excited  parts,  it  becomes,  as  compared  with  them 
(or  with  itself  under  the  previous  condition)  a  generator  of 
but  little  molecular  motion,  and  is  the  seat  of  that  faint 
feeling  which  we  distinguish  as  ideal.  In  brief,  those 
vivid  states  of  consciousness  which  we  know  as  sensations, 
accompany  direct  and  therefore  strong  excitations  of  nerve- 
centres;  while  the  faint  states  of  consciousness  which  we 
know  as  remembered  sensations,  or  ideas  of  sensations, 
accompany  indirect,  and  therefore  weak,  excitations  of 
the  same  nerve-centres. 

That  the  contrast  of  intensity  between  the  effects  of 
direct  and  indirect  excitations,  though  it  holds  generally, 
does  not  hold  without  exception,  is  a  fact  quite  reconcilable 
with  this  interpretation.  For,  on  the  one  hand,  a  direct 
excitation  may  be  very  feeble;  while,  on  the  other  hand, 
through  a  concurrence  of  diffused  disturbances,  an  indirect 


^STHO-PHYSIOLOGY.  125 

excitation  may  rise  to  considerable  strength.  Hence,  oc- 
casionally, an  ideal  feeling  will  become  almost  or  quite 
equal  in  vividness  to  a  real  feeling.  Especially  may  this 
happen  when  the  nerve-centre  concerned  is  surcharged  with 
blood;  since  a  small  disturbance  may  then  set  up  in  it  an 
amount  of  change  equal  to  that  which  a  great  disturbance 
produces  when  only  the  ordinary  quantity  of  blood  is  pre- 
sent. And  it  is  a  matter  of  observation  that  congested 
nerve-centres  are  those  in  which  indirectly-excited  feelings 
reach  an  intensity  scarcely  less  than  that  of  directly-excited 
feelings. 

When  we  pass  from  the  feelings  called  sensations,  of  which 
the  strong  forms  are  peripherally  initiated,  to  the  feelings 
called  emotions,  of  which  the  strong  forms  are  centrally 
initiated,  we  find  the  difference  between  the  strong  and  the 
weak  forms  by  no  means  so  great;  so  that,  in  fact,  ideal 
emotion  passes  into  actual  emotion  without  any  line  of  de- 
marcation. Obviously  this  is  what  might  be  anticipated. 
For  whether  ideal  or  actual,  emotion  is  an  accompaniment 
of  an  indirect  excitation:  it  is  not  an  immediate  result 
of  peripheral  impressions,  either  simple  or  combined; 
but  a  mediate  or  remote  result  of  them.  Hence,  all  emo- 
tions, vivid  and  faint,  being  the  subjective  aspects  of  ob- 
jective nervous  changes  that  are  produced  indirectly,  are 
distinguishable  only  according  to  the  degree  of  indirectness 
of  the  excitation,  and  this  admits  of  insensible  gradations. 

§  50.  One  more  general  truth  must  be  set  down  to  com- 
plete the  outline.  The  foregoing  inferences  joined  with 
some  contained  in  the  last  chapter,  introduce  us  to  it. 

In  §§36,  37,  it  was  pointed  out  that  nerve-centres  dis- 
integrated by  action,  are  perpetually  re-integrating  them- 
selves, and  again  becoming  fit  for  action.  We  saw  that 
repair  partially  makes  up  for  waste  from  instant  to  instant, 
and  that  the  arrears  of  repair  are  made  up  daily  during 
that  period  of  quiescence  when  waste  almost  ceases.     We 


X26  THE  DATA  OF  PSYCHOLOGY. 

further  saw  that  the  restoration  of  a  nerve-centre  to  its  state 
of  integrity,  is  not  only  the  filling  up  of  its  quantum  of  de- 
composable matter,  but  is  also  the  replacing  of  molecules 
most  exposed  to  disturbance,  and  consequently  the  produc- 
tion of  a  comparatively-unstable  state.  And  we  saw  how, 
after  a  period  of  profound  repose,  there  thus  arises  a  con- 
dition of  the  nerve-centres  such  that  very  slight  stimuK  cause 
nervous  discharges. 

This  law  applies  not  generally  only,  but  specially  to  each 
nerve-centre  and  each  of  its  component  parts.  In  propor- 
tion as  any  part  of  a  nerve-centre  has  been  for  a  long  time 
unused — in  proportion,  that  is,  as  repair  of  it  has  gone  on 
day  after  day  and  night  after  night  unhindered  by  appre- 
ciable waste,  it  must  be  brought  to  a  state  of  more  than 
ordinary  instability — a  state  of  excessive  readiness  to  de- 
compose and  discharge.  What  must  happen?  In  common 
with  all  other  parts,  it  is  exposed  to  these  reverberations 
which  from  instant  to  instant  fill  the  nervous  system.  Its 
extreme  instability  must  render  it  unusually  sensitive  to 
these  reverberations — unusually  ready  to  undergo  change, 
to  yield  up  molecular  motion,  and  to  become  the  seat  of 
the  concomitant  ideal  feeling.  Besides  a  great  liability 
to  the  ideal  feeling  this  same  condition  must  entail  a  great 
strength  of  it;  and  so  while  the  instability  continues,  a 
strong  ideal  feeling  will  be  perpetually  aroused.  As, 
however,  the  nerve-centre  in  which  such  secondary  mole- 
cular changes  and  accompanying  ideal  feelings  are  thus  set 
up,  is  somewhat  wasted  by  them,  it  follows  that  after  they 
have  gone  on  for  a  considerable  period  the  instability  of  the 
centre  will  be  diminished :  it  will  no  longer  be  so  easily  de- 
composed by  indirect  disturbances,  and  the  feeling  will  not 
be  produced. 

Here  we  have  the  interpretation  of  what  are  called 
desires.  Desires  are  ideal  feelings  that  arise  when  the 
real  feelings  to  which  they  correspond  have  not  been  ex- 
perienced for  some  time.    They  are  then  liable  to  be  excited 


^STHO-PHYSIOLOGY.  127 

by  various  of  the  indirect  disturbances  reflected  from  part 
to  part  of  the  nervous  system.  They  are  usually  vivid  and 
persistent  in  proportion  to  the  previous  period  of  rest — 
more  vivid  and  more  persistent  than  ideal  feelings  of  the 
same  kind  under  ordinary  conditions.  But  after  a  pro- 
longed period  during  which  they  continue  to  arise  and 
almost  monopolize  consciousness,  they  become  feebler  and 
finally  die  away. 

§  51.  Such  are  the  leading  truths  of  .^stho-Physiology, 
set  forth  with  as  much  fulness  as  is  here  requisite.  Sensa- 
tion and  emotion  in  their  relations  to  nervous  action,  have 
been  dealt  with  generally;  and  whatever  has  been  said  of 
special  sensations  and  special  emotions  has  been  said  merely 
to  illustrate  a  law  which  holds  among  all  the  rest.  The 
concomitants,  subjective  and  objective,  of  each  particular 
kind  of  sensation  and  each  particular  kind  of  emotion, 
I  here  pass  over.  They  may  be  studied  to  great  advantage 
in  the  works  of  Professor  Bain  on  The  Senses  cmd  the 
Intellect^  and  The  Emotions  cmd  the  Will;  in  which  he 
has  given  an  elaborate  account  of  the  connection  between 
each  particular  feeling,  simple  or  complex,  and  its  various 
physical  accompaniments.  To  these  works  I  must  com- 
mend the  reader  who  wishes  to  trace  out  these  minor  cor- 
relations. As  data  for  the  present  treatise,  the  only  facts 
needful  to  be  carried  with  us  are  those  set  forth  in  the 
preceding  sections.    They  may  be  summed  up  thus. 

Feeling  of  whatever  kind  is  directly  known  by  each 
person  in  no  other  place  than  his  own  consciousness.  That 
feelings  exist  in  the  world  beyond  consciousness,  is  a  belief 
reached  only  through  an  involved  combination  of  infer- 
ences. That  alike  in  human  and  inferior  beings,  feelings 
are  accompaniments  of  changes  in  the  peculiar  structure 
known  as  the  nervous  system,  is  also  an  indirectly- 
established  belief.  And  that  the  feelings  alone  cognizable 
by  any  individual  are  products  of  the  action  of  his  own 


128  THE  DATA  OF  PSYCHOLOGY. 

nervous  system,  which  he  has  never  seen  and  on  which  he 
can  try  no  experiments,  is  a  belief  only  to  be  arrived  at 
through  a  further  chain  of  reasoning.  Nevertheless,  the 
CAridence,  though  so  indirect,  is  so  extensive,  so  varied,  and 
so  congruous,  that  we  may  accept  the  conclusion  without 
hesitation. 

The  conclusion  having  been  accepted — provisionally  if 
not  permanently — its  validity  is  shown  by  leading  us  to 
anticipate  truly,  in  one  set  of  cases  after  another,  the  par- 
ticular subjective  phenomena  that  accompany  particular 
objective  phenomena.  We  have  seen  that  the  several 
circumstances  which  facilitate  or  hinder  nervous  action, 
are  also  circumstances  which  facilitate  or  hinder  feeling. 
We  have  seen  that  as  nervous  action  occupies  appreciable 
time,  so  feeling  occupies  appreciable  time.  We  have  seen 
that  each  feeling  leaves  a  partial  incapacity  for  a  like  feel- 
ing as  each  nervous  action  leaves  a  partial  incapacity  for 
a  like  nervous  action.  We  have  seen  that,  other  things 
equal;  the  intensities  of  feelings  vary  as  the  intensities  of 
the  correlative  nervous  actions.  We  have  seen  that  the 
difference  between  direct  and  indirect  nervous  disturbances, 
corresponds  to  the  difference  between  the  vivid  feelings 
we  call  real  and  the  faint  feelings  we  call  ideal.  And  we 
have  seen  that  certain  more  special  objective  phenomena 
which  nervous  actions  present,  have  answering  subjective 
phenomena  in  the  forms  of  feeling  we  distinguish  as  desires. 

Thus,  impossible  as  it  is  to  £^et  immediate  proof  that 
feeling  and  nervous  action  are  the  inner  and  outer  faces  of 
the  same  change,  yet  the  hypothesis  that  they  are  so 
harmonizes  with  all  the  observed  facts;  and,  as  elsewhere 
shown  {First  PrirtGiples^  §  40)  no  other  verification  is  pos- 
sible for  us  than  that  which  results  from  the  establishment 
of  complete  congniity  among  our  experiences. 


CHAPTER  Vn. 


THE    SCOPE    OF    PSYCHOLOGY. 


§  52.  We  may  now  enter  on  our  special  topic.  Thus  far 
we  have  been  occupied  with  the  data  of  Psychology,  and 
not  with  Psychology  properly  so-called.  Here  leaving  the 
foundations  we  pass  to  the  superstructure. 

Not  a  few  readers  will  be  surprised  by  the  assertion  that 
none  of  the  truths  we  have  been  contemplating  are  psycho- 
logical truths.  Since  the  anatomy  and  physiology  of  the 
nervous  system  have  occupied  so  much  attention,  and  since 
it  has  been  growing  manifest  that  there  is  a  fundamental 
connection  between  nervous  changes  and  psychical  states, 
there  has  arisen  a  confusion  between  the  phenomena  which 
underlie  Psychology  and  the  phenomena  of  Psychology  it- 
self. In  reality,  all  the  facts  ascertained  by  those  who  have 
made  nerve-structure  and  nerve-function  their  studies,  are 
facts  of  a  simpler  order  than  those  rightly  termed  psycho- 
logical; though  they  are  facts  entering  into  the  composi- 
tion of  psychological  facts. 

Most  will  admit  without  hesitation  that  the  first  five 
chapters  of  this  part  consist  of  propositions  which  are  exclu- 
sively morphological  and  physiological.  In  them  the  struc- 
ture of  the  nervous  system,  its  functions,  the  conditions 
to  its  action,  &c.,  have  been  dealt  with  purely  as  physical 
phenomena — phenomena  as  purely  physical  as  the  absorp- 


130  THE  DATA  OF  PSYCHOLOGY. 

tion  of  nutriment  or  the  circulation  of  the  blood.  Whatever 
implications  may  have  arisen  from  the  use  of  words  that 
carry  with  them  indirect  meanings,  the  direct  meanings  of 
all  the  propositions  set  down  have  nowhere  implied  con- 
sciousness or  feeling;  and,  ignoring  consciousness  or  feeling, 
they  have  left  out  that  which  is  tacitly  or  avowedly  contained 
in  every  proposition  of  Psychology. 

It  will  probably  be  thought,  however,  that  at  any  rate 
truths  belonging  to  Psychology  proper  are  to  be  found 
in  the  last  chapter.  Dealing  as  the  last  chapter  does  with 
the  connections  between  nervous  changes  and  feelings,  it 
necessarily  becomes,  by  including  a  psychical  element,  a  part 
of  psychical  science.  To  this  the  rejoinder  is  that,  though 
it  can  scarcely  be  excluded  absolutely  from  the  body  of  this 
science,  yet  it  does  not  strictly  fall  within  that  body,  ^stho- 
physiology  has  a  position  that  is  entirely  unique.  It  belongs 
neither  to  the  objective  world  nor  the  subjective  world;  but 
taking  a  term  from  each,  occupies  itself  with  the  correlation 
of  the  two.  It  may  with  as  much  propriety  be  included 
in  the  domain  of  physical  science  as  in  the  domain  of  psy- 
chical science;  and  must  be  left  where  it  stands,  as  the 
link  between  them. 

Perhaps  this  explanation  will  increase  rather  than  decrease 
the  surprise  produced  by  the  assertion  that  was  to  be  justi- 
fied. To  clear  up  the  confusion,  we  must  examine  more 
carefully  the  distinction  between  the  truths  which  are 
strictly  psychological  and  those  which  merely  enter  into 
the  composition  of  psychological  truths. 

§  53.  Throughout  the  preceding  chapters,  including  even 
the  last,  every  proposition  set  down  has  expressed  some 
relation  of  phenomena  occurring  within  the  limits  of  the 
organism.  The  subject-matter  has  been  the  character  of 
a  structure ;  or  the  effect  which  a  disturbance  set  up  in  one 
place  has  in  causing  motion  in  another;  or  the  connection 
between  the  physical  state  of  the  whole  or  a  part  of  the 


THE  SCOPE  OF  PSYCHOLOGY.  131 

organism,  and  some  general  or  local  nervous  process;  on 
the  variable  intensity  of  an  action  in  a  nerve-centre  as 
determined  by  a  preceding  like  action;  or  the  interdepen- 
dence of  internal  physical  changes  and  internal  psychical 
changes.  That  is  to  say,  the  attention  has  everywhere  been 
directed  exclusively  to  co-existences  and  sequences  of  which 
the  body  alone  is  the  sphere.  Distinct  or  tacit 

reference  has,  indeed,  frequently  been  made  to  some  external 
force.  Either  a  disturbing  agent  lying  beyond  the  limits  of 
the  organism  has  been  referred  to  in  general  terms,  or,  for 
illustration's  sake,  this  or  the  other  kind  of  disturbing  agent 
has  been  named.  But  such  references,  vague  or  distinct, 
have  been  made  merely  because  it  was  needful  to  suppose 
something  by  which  an  organic  change  was  set  up;  not 
because  this  something  had  to  be  included  in  the  proposi- 
tion set  down,  which  in  every  case  formulated  an  internal 
relation  only.  The  entanglement  of  phenomena  is  such,  that 
we  can  never  cut  off  absolutely  from  all  others  the  par- 
ticular phenomena  we  are  dealing  with;  but,  because  we 
presuppose  these  other  phenomena,  it  does  not  follow  that 
the  science  to  which  they  pertain  forms  part  of  the  science 
with  which  we  are  specially  occupied.  For  instance,  it  is 
impossible  to  describe,  or  think  of,  a  chemical  experiment 
that  discloses  some  chemical  relation,  without  making  dis- 
tinct or  tacit  references  to  physical  relations — the  pouring 
and  mixture  of  liquids,  the  ascent  of  bubbles  of  disengaged 
gas,  the  falling  of  a  precipitate ;  but  it  is  not  therefore  held 
that  we  are  including  physics  in  our  chemistry.  Similarly, 
it  must  be  admitted  that  though  the  foregoing  chapters 
have  tacitly  assumed  environing  forces,  yet  this  assumption 
has  been  simply  incidental  to  the  study  of  internal  co- 
existences and  sequences. 

Now  so  long  as  we  state  facts  of  which  all  the  terms  lie 
within  the  organism,  our  facts  are  morphological  or  phy- 
siological and  in  no  degree  psychological.     Even  though 
the  relation  with  which  we  are  dealing  is  that  between  a 
10 


132  THE  DATA  OF  PSYCHOLOGY. 

nervous  change  and  a  feeling,  it  is  still  not  a  psychological 
relation  so  long  as  the  feeling  is  regarded  merely  as  con- 
nected with  the  nervous  change,  and  not  as  connected  with 
some  existence  lying  outside  the  organism.  As  certainly  as 
the  man  who  demonstrates  by  dissection  the  articulations  of 
the  bones,  and  the  man  who,  by  a  sphygmograph,  delineates 
the  varying  motions  of  the  heart,  are  respectively  studying 
morphology  and  physiology;  so  certainly  is  the  man  who 
examines  nervous  structure  and  experiments  on  nervous 
function,  a  student  of  these  same  sciences,  if  he  considers 
the  inner  correlations  only  and  does  not  simultaneously 
consider  the  answering  outer  correlations. 

For  that  which  distinguishes  Psychology  from  the  sciences 
on  which  it  rests,  is,  that  each  of  its  propositions  takes  ac- 
count both  of  the  connected  internal  phenomena  and  of  the 
connected  external  phenomena  to  which  they  refer.  In  a  phy- 
siological proposition  an  inner  relation  is  the  essential  sub- 
ject of  thought ;  but  in  a  psychological  proposition  an  outer 
relation  is  joined  with  it  as  a  co-essential  subject  of  thought. 
A  relation  in  the  environment  rises  into  co-ordinate  im- 
portance with  a  relation  in  the  organism.  The  thing  con- 
templated is  now  a  totally  different  thing.  It  is  not  the 
connection  between  the  internal  phenomena,  nor  is  it  the 
connection  between  the  external  phenomena;  but  it  is  the 
connection  between  these  two  corwiections.  A  psychological 
proposition  is  necessarily  compounded  of  two  propositions, 
of  which  one  concerns  the  subject  and  the  other  concerns 
the  object;  and  cannot  be  expressed  without  the  four  terms 
which  these  two  propositions  imply.  The  distinction  may 
be  best  explained  by  symbols.  Suppose  that  A  and  B  are 
two  related  manifestations  in  the  environment — say,  the 
colour  and  taste  of  a  fruit ;  then,  so  long  as  we  contemplate 
their  relation  by  itself,  or  as  associated  with  other  external 
phenomena,  we  are  occupied  with  a  portion  of  physical 
science.  Now  suppose  that  a  and  h  are  the  sensations  pro- 
duced in  the  organism  by  this  peculiar  light  which  the  fruit 


THE  SCOPE  OP  PSYCHOLOGY.  133 

reflects,  and  by  the  chemical  action  of  its  juice  on  the 
palate;  then,  so  long  as  we  study  the  action  of  the  light  on 
the  retina  and  optic  centres,  and  consider  how  the  juice  sets 
up  in  other  centres  a  nervous  change  known  as  sweetness, 
we  are  occupied  with  facts  belonging  to  the  sciences  of 
Physiology  and  ^stho-physiology.  But  we  pass  into  the 
domain  of  Psychology  the  moment  we  inquire  how  there 
comes  to  exist  within  the  organism  a  relation  between  a  and 
h  that  in  some  way  or  other  corresponds  to  the  relation 
between  A  and  B.  Psychology  is  exclusively  concerned 
with  this  connection  between  (A  B)  and  (a  6) — has  to  in- 
vestigate its  nature,  its  origin,  its  meaning,  &c. 

A  moment's  introspection  will  now  make  it  clear  to  the 
reader,  that  he  cannot  frame  any  psychological  conception 
without  thus  looking  at  internal  co-existences  and  se- 
quences in  their  adjustments  to  external  co-existences 
and  sequences.  If  he  studies  the  simplest  act  of  per- 
ception, as  that  of  localizing  a  touch  in  some  part  of  his 
skin,  the  indispensable  terms  of  his  inquiry  are: — on  the 
one  hand  a  thing  (1)  and  a  position  (2),  both  of  which 
he  regards  as  objective;  and  on  the  other  hand  a  sensation 
(3),  and  a  state  of  consciousness  constituting  his  apprehen- 
sion of  position  (4),  both  of  which  he  regards  as  subjective. 
Again,  to  cite  an  example  from  the  opposite  extreme, 
if  he  takes  for  his  problem  one  of  his  involved  sentiments, 
as  that  of  justice,  he  cannot  represent  to  himself  this 
sentiment,  or  give  any  meaning  to  its  name,  without  calling 
to  mind  actions  and  relations  supposed  to  exist  in  the 
environment:  neither  this  nor  any  other  emotion  can  be 
aroused  in  consciousness  even  vaguely,  without  positing 
something  beyond  consciousness  to  which  it  refers.  And 
when,  instead  of  studying  Psychology  subjectively,  he 
studies  it  objectively  in  the  acts  of  other  beings,  he 
similarly  finds  himself  incapable  of  stirring  a  step  with- 
out thinking  of  inner  correlations  in  their  references  to 
outer  correlations. 


134  THE  SCOPE  OF  PSYCHOLOGY. 

§  54.  It  is  contended  by  some  that  Psychology  is  a  part 
of  Biology,  and  should  be  merged  in  it ;  and  those  who  hold 
this  view  will  possibly  answer  the  above  argument  by 
saying  that  in  many  cases  the  non-psychological  part  of 
Biology  also  takes  into  account  phenomena  in  the  environ- 
ment, and  even  definite  connections  among  these  pheno- 
mena. The  life  of  every  organism  is  a  continuous  adapta- 
tion of  its  inner  actions  to  outer  actions;  and  a  complete 
interpretation  of  the  inner  actions  involves  recognition 
of  the  outer  actions.  The  annual  production  of  leaves, 
flowers,  and  seeds  by  plants,  is  adjusted  to  the  annual 
changes  of  the  seasons;  and  there  is  in  animals  an  adjust- 
ment between  external  changes  in  temperature  and  abund- 
ance, and  internal  production  of  ova.  Moreover,  there  are 
many  special  relations  of  structure  and  function  in  plants 
and  animals,  that  have  reference  to  special  relations  of  struc- 
ture and  function  in  surrounding  plants  and  animals:  in- 
stance those  arrangements  of  the  sexual  organs  that  fit 
particular  phsenogams  for  being  fertilized  by  the  particular 
insects  that  visit  them. 

But  true  as  is  this  conception  of  Life  (and  having  based 
the  Principles  of  Biology  on  it  I  am  not  likely  to  question 
or  to  undervalue  it),  I  nevertheless  hold  the  distinction 
above  drawn  to  be  substantially  valid.  For  through- 
out Biology  proper,  the  environment  and  its  correlated 
phenomena  are  either  but  tacitly  recognized,  or,  if  overtly 
and  definitely  recognized,  are  so  but  occasionally;  while 
the  organism  and  its  correlated  phenomena  practically 
monopolize  the  attention.  But  in  Psychology,  the  cor- 
related phenomena  of  the  environment  are  at  every  step 
avowedly  and  distinctly  recognized;  and  are  as  essential 
to  every  psychological  idea  as  are  the  correlated  phe- 
nomena of  the  organism.  Let  us  observe  the  contrast 
as  exemplified.  We  study  digestion.  Digestion  implies 
food.  Food  implies  neighbouring  plants  or  animals.  But 
this  implication  scarcely  enters  into  our  study  of  digestion, 


THE  SCOPE  OP  PSYCHOLOGY.  135 

unless  we  ask  the  quite  special  question — how  the  digestive 
organs  become  fitted  to  the  materials  they  have  to  act  upon? 
Again,  when  we  interpret  respiration  we  take  for  granted  a 
surrounding  oxygenated  medium.  And  yet  to  show  how 
far  the  two  may  be  separated,  we  need  only  remember  that 
the  phenomena  of  respiration  may  be  very  well  traced  out 
in  one  who  breathes  a  bladder  of  gas  artificially  obtained 
from  peroxide  of  manganese  or  chlorate  of  potash.  Once 
more,  if,  in  following  out  the  life-history  of  a  plant,  we  have 
to  note  the  adaptation  of  its  hooked  seeds  to  the  woolly 
fleece  of  the  animal  which  accidentally  carries  them  off  and 
disperses  them,  this  distinct  reference  to  specially-connected 
phenomena  in  the  environment,  occurs  either  but  once  in  an 
account  of  the  plant's  life,  or  only  at  long  intervals.  In  fact, 
we  may  say  that  the  great  mass  of  purely  biological  pheno- 
mena may  be  displayed  for  some  time  by  an  organism  de- 
tached from  its  medium,  as  by  a  fish  out  of  water.  Now 
observe  how  different  it  is  with  psychological  phenomena. 
We  cannot  explain  a  single  act  of  a  fish  as  it  moves  about 
in  the  water,  without  taking  into  account  its  relations  to 
neighbouring  objects  distinguished  by  specially-related 
attributes.  The  instinctive  proceedings  of  the  insect, 
equally  with  those  which  in  higher  creatures  we  call  in- 
telligent, we  are  unable  even  to  express  without  referring 
to  things  around. 

In  brief,  then,  the  propositions  of  Biology,  when  they 
imply  the  environment  at  all,  imply  almost  exclusively  its 
few  general  and  constant  phenomena,  which,  because  of 
their  generality  and  constancy,  may  be  left  out  of  con- 
sideration; whereas  the  propositions  of  Psychology  refer 
to  its  multitudinous,  special,  and  ever-varying  phenomena, 
which,  because  of  their  speciality  and  changeability,  can- 
not be  left  out  of  consideration. 

§  55.  The  admission  that  Psychology  is  not  demarcated 
from  Biology  by  a  sharp  line,  will  perhaps  be  construed 


136  THE  DATA  OF  PSYCHOLOGY. 

into  the  admission  that  it  cannot  rightly  be  regarded  as  a 
distinct  science.  But  those  who  so  construe  the  admission, 
misconceive  the  natures  of  the  relations  among  the  sciences. 
They  assume  that  there  exist  objectively  those  clear  separa- 
tions which  the  needs  of  classification  lead  us  to  make 
subjectively.  Whereas  the  fact  is,  that  beyond  the  divisions 
between  the  three  fundamental  orders  of  the  sciences,  Ab- 
stract, Abstract-concrete,  and  Concrete,  there  exist  ob- 
jectively no  clear  separations  at  all:  there  are  only  differ- 
ent groups  of  phenomena  broadly  contrasted  but  shading 
off  one  into  another.  To  those  who  accept  the  doctrine  of 
Evolution,  this  scarcely  needs  saying;  for  Evolution  being 
a  universal  process,  one  and  continuous  throughout  all 
forms  of  existence,  there  can  be  no  break — no  change  from 
one  group  of  concrete  phenomena  to  another  without  a 
bridge  of  intermediate  phenomena.  It  will  be  well  here, 
however,  to  show  by  illustrations  that  the  simpler  concrete 
sciences  are  separable  from  one  another  only  in  the  same 
way  that  Psychology  is  separable  from  Biology. 

Astronomy  and  Geology  are  regarded  as  distinct.  But 
Geology  is  nothing  more  than  a  chapter  continuing  in 
detail  one  part  of  a  history  that  was  once  wholly  astrono- 
mic; and  even  now,  many  of  its  leading  facts  belong  as 
much  to  the  older  part  of  the  history  as  to  the  younger. 
Not  only  do  we  trace  back  the  Earth  to  a  time  when  its 
astronomic  attributes  were  uncomplicated  by  those  geo- 
logic ones  that  have  gradually  arisen  as  it  cooled;  not  only 
in  the  solar  heat,  causing  the  aerial,  marine,  and  fluvial 
currents  which  work  most  geologic  changes,  are  we  com- 
pelled to  recognize  an  astronomic  force;  but  in  the  tidal 
wave  we  have  a  phenomenon  as  much  astronomic  as  geo- 
logic, and  as  much  geologic  as  astronomic.  Even  he  who 
arbitrarily  excludes  from  astronomy  everything  but  the 
molar  motions  throughout  the  Solar  System  (so  ignoring 
the  radiant  light  and  heat  by  which  alone  the  Sun  and 
planets  are  known  to  us)  does  not  escape  this  difficulty; 


THE  SCOPE  OF  PSYCHOLOGY.  137 

for  the  motion  of  the  tidal  wave  is  a  molar  motion  gene- 
rated by  forces  such  as  generate  all  other  molar  motions 
exhibited  by  the  Solar  System;  and  yet  it  is  at  the  same 
time  a  motion  of  matter  on  the  Earth's  surface,  not  dis- 
tinguishable from  those  other  motions  of  matter  which 
constitute  geological  changes,  many  of  which,  indeed,  are 
concomitants  of  it.  The  separation  between  Bio- 

logy and  Geology  once  seemed  impassable;  and  to  many 
seems  so  now.  But  every  day  brings  new  reasons  for 
believing  that  the  one  group  of  phenomena  has  grown  out 
of  the  other.  Organisms  are  highly-differentiated  portions 
of  the  matter  forming  the  Earth's  crust  and  its  gaseous 
envelope;  and  their  differentiation  from  the  rest  has 
arisen,  like  other  differentiations,  by  degrees.  The  chasm 
between  the  inorganic  and  the  organic  is  being  filled  up. 
On  the  one  hand,  some  four  or  five  thousand  compounds  once 
regarded  as  exclusively  organic,  have  now  been  produced 
artificially  from  inorganic  matter;  and  chemists  do  not 
doubt  their  ability  so  to  produce  the  highest  forms  of 
organic  matter.  On  the  other  hand,  the  microscope  has 
traced  down  organisms  to  simpler  and  simpler  forms  until, 
in  the  Protogenes  oi  Professor  Plaeckel,  there  has  been 
reached  a  type  distinguishable  from  a  fragment  of  albumen 
only  by  its  finely-granular  character. 

Thus  the  distinction  between  Biology  and  Psychology  has 
the  same  justification  as  the  distinctions  between  the  con- 
crete sciences  below  them.  Theoretically,  all  the  concrete 
sciences  are  adjoining  tracts  of  one  science,  which  has  for 
its  subject-matter,  the  continuous  transformation  which  the 
Universe  undergoes.  Practically,  however,  they  are  dis- 
tinguishable as  successively  more  specialized  parts  of  the 
total  science — parts  further  specialized  by  the  introduction 
of  additional  factors.  The  Astronomy  of  the  Solar  System  is 
a  specialized  part  of  that  general  Astronomy  which  includes 
our  whole  Sidereal  System;  and  becomes  specialized  by 
taking  into  account  the  revolutions  and  rotations  of  planets 


138  THE  DATA  OF  PSYCHOLOGY. 

and  satellitea.  Geology  (or  rather  Geogeny  let  us  call  it, 
that  we  may  include  all  those  mineralogical  and  meteorologi- 
cal changes  which  the  word  Geology,  as  now  used,  recognizes 
but  tacitly)  is  a  specialized  part  of  this  special  Astronomy; 
and  becomes  specialized  by  joining  with  the  effects  of  the 
Earth's  molar  motions,  the  effects  of  continuous  decrease  in 
its  internal  molecular  motion,  and  the  effects  of  the  molecular 
motion  radiated  from  the  Sun.  Biology  is  a  specialized  part 
of  Geogeny,  dealing  with  peculiar  aggregates  of  peculiar 
chemical  compounds  formed  of  the  Earth's  superficial 
elements — aggregates  which,  while  exposed  to  these  same 
general  forces  molar  and  molecular,  also  exert  certain 
general  actions  and  reactions  on  one  another.  And  Psy- 
chology is  a  specialized  part  of  Biology,  limited  in  its  appli- 
cation to  the  higher  division  of  these  peculiar  aggregates, 
and  occupying  itself  exclusively  with  those  special  actions 
and  reactions  which  they  display,  from  instant  to  instant, 
in  their  converse  with  the  special  objects,  animate  and  in- 
animate, amid  which  they  move- 
But  this  introduction  of  additional  factors,  which  differ- 
entiates each  more  special  science  from  the  more  general 
science  including  it,  fails  in  every  case  to  differentiate  it 
absolutely;  because  the  introduction  of  the  additional 
factors  is  gradual.  It  is  so  not  with  the  Concrete  Sciences 
alone,  but  even  with  the  Abstract-concrete  Sciences,  which 
at  first  sight  seem  sharply  demarcated;  as,  for  instance. 
Physics  and  Chemistry.  Physics,  dealing  with  changes  in 
the  distribution  of  matter  and  motion  considered  apart 
from  unlikenesses  of  quality  in  the  matter,  is  obliged  to 
include  in  its  inquiries  all  the  molecular  integrations  and 
disintegrations  caused  by  alterations  of  temperature — the 
meltings  and  evaporations  which  increase  of  heat  produces, 
as  well  as  the  condensations  and  crystallizations  which  follow 
decrease  of  heat.  Among  other  molecular  transformations 
resulting  from  losses  and  gains  of  molecular  motion,  are 
those  known  as  allotropio — transformations  which,  without 


THE  SCOPE  OP  PSYCHOLOGY.  139 

appreciably  altering  the  degrees  of  integration,  leave  the 
molecules  so  re-arranged  that  they  exhibit  new  properties  of 
the  order  we  call  chemical;  as  is  shown  by  their  changed 
affinities  for  the  molecules  of  other  substances,  and  by  their 
changed  effects  on  our  nerves  of  sense.  Must  we  class  such 
molecular  transformations  as  physical  phenomena,  because 
in  each  case  the  molecules  concerned  are  all  of  one  kind? 
If  so,  what  are  we  to  say  of  isomeric  transformations,  which 
all  chemists  recognize  as  of  essentially  the  same  nature? 
In  these,  molecules  of  different  kinds  are  concerned.  And 
if,  because  they  show  us  a  re-distribution  of  heterogeneous 
molecules  instead  of  homogeneous  ones,  we  put  them  in  the 
category  of  chemical  phenomena,  we  arbitrarily  dissociate 
two  fundamentally-similar  classes  of  facts.  Perhaps  it  will 
be  replied  that  in  isomeric  transformations  the  molecules  a/re 
homogeneous,  relatively  to  the  re-distribution  they  undergo; 
that  each  of  them,  retaining  its  individuality  unchanged, 
comports  itself  towards  the  rest  as  though  it  were  a  simple 
molecule;  that  nothing  more  takes  place  than  a  re-grouping 
of  these  unchanged  molecules;  and  that  there  is  thus  an 
absence  of  what  constitutes  a  truly  chemical  change — union 
or  disunion  of  unlike  molecules.  The  reply  is  plausible,  but 
it  is  easily  disposed  of.  For  there  are  transformations  of 
this  nature  in  which  such  unions  and  disunions  occur.  A 
colloid  compound  in  passing  from  one  of  its  isomeric  forms 
to  another,  very  generally  parts  with  some  of  its  contained 
water,  or  takes  up  additional  water.  Does  this  make  the 
change  a  chemical  one?  Then  we  must  relegate  to  the 
domain  of  Physics  that  isomerism  which  is  not  accompanied 
by  loss  or  gain  of  water,  and  include  in  the  domain  of  Che- 
mistry that  isomerism  which  is  so  accompanied — a  very 
artificial  disunion  of  the  sciences,  to  which  I  think  neither 
Physicists  nor  Chemists  will  agree.  !N^evertheless,  un- 
decided as  is  the  line  which  separates  them,  we  are  not 
prevented  from  recognizing  the  broad  distinction  between 
Molecular  Physics  and  Chemistry.    The  new  factor  which 


140  THE  DATA  OF  PSYCHOLOGY. 

differentiates  Chemistry  from  Molecular  Physics,  is  the 
heterogeneity  of  the  molecules  with  whose  re-distributions 
it  deals.  And  the  contrast  hence  resulting  is  too  strongly 
marked  to  be  obliterated  by  transitional  cases. 

In  this  way  it  is,  then,  that  the  conspicuous  presence 
of  additional  factors  differentiates  Psychology  from  Biology 
proper;  although  in  Biology  proper  these  factors  make  an 
occasional  appearance.  The  contrast  between  the  two  is  no 
more  destroyed  by  such  community  as  exists,  than  is  the 
contrast  between  night  and  day  destroyed  by  the  occurrence 
of  a  dawn  which  belongs  as  much  to  one  as  to  the  other. 

§  56.  A  far  more  radical  distinction  remains  to  be  drawn. 
While,  under  its  objective  aspect.  Psychology  is  to  be  classed 
as  one  of  the  concrete  sciences  which  successively  decrease 
in  scope  as  they  increase  in  speciality;  under  its  subjective 
aspect.  Psychology  is  a  totally  unique  science,  independent 
of,  and  antithetically  opposed  to,  all  other  sciences  whatever. 
The  thoughts  and  feelings  which  constitute  a  consciousness, 
and  are  absolutely  inaccessible  to  any  but  the  possessor  of 
that  consciousness,  form  an  existence  that  has  no  place 
among  the  existences  with  which  the  rest  of  the  sciences 
deal.  Though  accumulated  observations  and  experiments 
have  led  us  by  a  very  indirect  series  of  inferences  (§  41)  to 
the  belief  that  mind  and  nervous  action  are  the  subjective 
and  objective  faces  of  the  same  thing,  we  remain  utterly  in^ 
capable  of  seeing,  and  even  of  imagining,  how  the  two  are 
related.  Mind  still  continues  to  us  a  something  without  any 
kinship  to  other  things;  and  from  the  science  which  dis' 
covers  by  introspection  the  laws  of  this  something,  there  ia 
no  passage  by  transitional  steps  to  the  sciences  which  dis- 
cover the  laws  of  these  other  things. 

Following  M.  Comte,  there  are  a  few  who  assert  that  a 
subjective  Psychology  is  impossible;  and  to  such  the  above 
paragraph  will,  I  suppose,  be  meaningless.  But  whoever 
recognizes  a  subjective  Psychology,  and  admits,  as  he  must, 


THE  SCOPE  OP  PSYCHOLOGY.  141 

tiiat  without  it  there  can  be  no  objective  Psychology,  there- 
upon finds  himself  obliged  to  assign  a  quite  special  rank, 
not  to  the  first  only,  but,  by  implication,  to  the  second.  To 
those  who  see  that  the  essential  conceptions  on  which  Psy- 
chology in  general  proceeds,  are  funished  by  subjective 
Psychology — to  those  who  see  that  such  words  as  feelings, 
ideas,  memories,  volitions,  have  acquired  their  several  mean- 
ings through  self-analysis,  and  that  the  distinctions  we 
make  between  sensations  and  emotions,  or  between  auto- 
matic acts  and  voluntary  acts,  can  be  established  only  by 
comparisons  among,  and  classifications  of,  our  mental  states; 
it  will  be  manifest  that  objective  Psychology  can  have  no 
existence  as  such,  without  borrowing  its  data  from  sub- 
jective Psychology.  And  thus  perceiving  that,  until  it 
acknowledges  its  indebtedness  to  subjective  Psychology, 
objective  Psychology  cannot  legitimately  use  any  terms  that 
imply  consciousness,  but  must  limit  itself  to  nervous  co- 
ordinations considered  as  physical  only;  they  will  see  that 
even  objective  Psychology  contains  an  element  which  differ- 
entiates it  from  the  rest  of  the  special  concrete  sciences 
more  than  any  of  these  are  differentiated  from  one  another. 
The  claims  of  Psychology  to  rank  as  a  distinct  science, 
are  thus  not  smaller  but  greater  than  those  of  any  other 
science.  If  its  phenomena  are  contemplated  objectively, 
merely  as  nervo-muscular  adjustments  by  which  the  higher 
organisms  from  moment  to  moment  adapt  their  actions  to 
environing  co-existences  and  sequences,  its  degree  of 
speciality,  even  then,  entitles  it  to  a  separate  place.  The 
moment  the  element  of  feeling,  or  consciousness,  is  used 
to  interpret  nervo-muscular  adjustments  as  thus  exhibited 
in  the  living  beings  around,  objective  Psychology  acquires 
an  additional,  and  quite  exceptional,  distinction.  And  it  is 
further  distinguished  in  being  linked  by  this  common 
element  of  consciousness,  to  the  totally-independent  science 
of  subjective  Psychology — the  two  forming  together  a 
double  science  which,  as  a  whole,  is  quite  sui  generis. 


142  THE  DATA  OF  PSYCHOLOGY. 

§  67.  So  understanding  its  scope,  we  are  now  prepared  to 
enter  on  the  study  of  Psychology  proper.  The  foregoing 
discussion  serves  not  unfitly  to  introduce  the  several  divi- 
sions into  which  the  entire  subject  falls. 

First  come  the  Inductions  of  Psychology;  under  which 
title  we  will  deal  with  the  leading  empirical  generaliza- 
tions— presenting  them,  however,  under  an  aspect  some- 
what different  from  the  usual  one.  And  the  truths  in- 
ductively reached  will,  when  possible,  be  elucidated  deduc- 
tively, by  affiliating  them  on  the  truths  of  Neuro-physiology 
and  ^stho-physiology  set  down  in  the  foregoing  chapters. 

We  will  next  pass  to  Objective  Psychology;  of  which 
three  divisions  may  conveniently  be  made.  In  the  first,  or 
General  Synthesis,  we  will  trace  throughout  the  animal 
kingdom,  the  progress  in  these  perpetual  adjustments  of 
special  inner  actions  to  special  outer  actions,  which  accom- 
panies increasing  evolution  of  the  nervous  system — omitting, 
so  far  as  may  be,  the  element  of  consciousness.  In  the 
second,  or  Special  Synthesis,  we  will  consider  this  same 
progress  more  closely,  with  the  view  of  delineating  and 
formulating  it  in  terms  that  imply  consciousness.  And  in 
the  third,  or  Physical  Synthesis,  an  endeavour  will  be  made 
to  show  how,  by  an  ultimate  principle  of  nervous  action, 
this  progress  is  explicable  as  part  of  Evolution  in  general. 

Turning  then  to  Subjective  Psychology,  the  natures  of 
particular  modes  of  consciousness,  as  ascertained  by  in- 
trospection, will  first  be  treated  under  the  head  of  Special 
Analysis.  And  then,  under  the  head  of  General  Analysis, 
we  will  enter  upon  the  ultimate  question  of  the  relation 
between  Thought  and  Things. 

Two  remaining  divisions  will  be  devoted,  the  one  to  a 
comparison  between  the  results  reached  in  the  preceding 
divisions,  with  a  view  of  showing  their  congruity,  and  the 
other  to  a  series  of  corollaries  constituting  that  special  part 
of  Human  Psychology  on  which  Sociology  must  be  based. 


PART    II. 


THE   INDUCTIONS   OF   PSYCHOLOGY, 


CHAPTER  I. 


THE    SUBSTANCE    OF    MIND. 


§  58.  To  write  a  chapter  for  the  purpose  of  showing  that 
nothing  is  known,  or  can  be  known,  of  the  subject  which  the 
title  of  the  chapter  indicates,  will  be  thought  strange.  It  is, 
however,  in  this  case  needful — needful  because,  in  the  ab- 
sence of  explanation,  much  that  has  gone  before,  and  much 
that  will  come  hereafter,  may  be  misinterpreted ;  and  needful 
also  because  we  have  to  distinguish  between  that  absolute 
ignorance  and  that  partial  knowledge  which  may  be  asserted 
according  as  we  give  one  or  other  meaning  to  the  terms 
used. 

For  if  by  the  phrase  "  substance  of  Mind,"  is  to  be  under- 
stood Mind  as  qualitatively  differentiated  in  each  portion 
that  is  separable  by  introspection  but  seems  homogeneous 
and  undecomposable ;  then  we  do  know  something  about 
the  substance  of  Mind,  and  may  eventually  know  more.  As- 
suming an  underlying  something,  it  is  possible  in  some  cases 
to  see,  and  in  the  rest  to  conceive,  how  these  multitudinous 
modifications  of  it  arise.  But  if  the  phrase  is  taken  to  mean 
the  underlying  something  of  which  these  distinguishable 
portions  are  formed,  or  of  which  they  are  modifications; 
then  we  know  nothing  about  it,  and  never  can  know  any- 
thing about  it.  It  is  not  enough  to  say  that  such  knowledge 
is  beyond  the  grasp  of  human  intelligence  as  it  now  exists; 
for  no  amount  of  that  which  we  call  intelligence,  however 

transcendent,  can  grasp  such  knowledge. 

145 


146  THE  INDUCTIONS  OF  PSYCHOLOGY. 

These  two  propositions  will  need  a  good  deal  of  elucida- 
tion. It  will  be  most  convenient  to  deal  first  with  the  last 
of  them. 

§  59.  To  meet  all  imaginable  possibilities,  let  us  set  out 
with  the  doctrine  of  Hume,  that  impressions  and  ideas  are 
the  only  things  known  to  exist,  and  that  Mind  is  merely  a 
name  for  the  sum  of  them.  In  this  case,  the  expression 
"  substance  of  Mind  "  can  have  no  meaning,  unless  as  ap- 
plied to  each  or  any  impression  or  idea  individually.  Whence 
it  follows  that  there  are  as  many  different  substances  of 
Mind  as  there  are  different  impressions  and  ideas;  and  this 
amounts  to  the  conclusion  that  there  is  no  substance  of  Mind 
in  the  sense  implied;  or,  at  any  rate,  that  we  have  no  evi- 
dence of  its  existence.  A  fortioH,  the  substance  of  Mind 
cannot  be  known. 

Contrariwise,  let  us  yield  to  the  necessity  of  regarding 
impressions  and  ideas  as  forms  or  modes  of  a  continually- 
existing  something.  Failing  in  every  effort  to  break  the 
series  of  impressions  and  ideas  in  two,  we  are  prevented 
from  thinking  of  them  as  separate  existences.  While  each 
particular  impression  or  idea  can  be  absent,  that  which 
holds  impressions  and  ideas  together  is  never  absent; 
and  its  unceasing  presence  necessitates,  or  indeed  con- 
stitutes, the  notion  of  continuous  existence  or  reality. 
Existence  means  nothing  more  than  persistence;  and 
hence  in  Mind  that  which  persists  in  spite  of  all 
changes,  and  maintains  the  unity  of  the  aggregate  in 
defiance  of  all  attempts  to  divide  it,  is  that  of  which  ex- 
istence in  the  full  sense  of  the  word  must  be  predicated — 
that  which  we  must  postulate  as  the  substance  of  Mind  in 
contradistinction  to  the  varying  forms  it  assumes.  But  if 
so,  the  impossibility  of  knowing  the  substance  of  Mind  is 
manifest.  By  the  definition,  it  is  that  which  under- 
goes the  modification  producing  a  state  of  Mind.  Con- 
sequently, if  every  state  of  Mind  is  some  modification  of 


THE  SUBSTANCE  OP  MIND.  I47 

this  substance  of  Mind,  there  can  be  no  state  of  mind  in 
which  the  unmodified  substance  of  Mind  is  present. 

Knowing  implies  something  acted  upon  and  something 
acting  upon  it.  To  see  that  this  is  undeniable  we  have  but 
to  glance  at  the  three  intelligible  propositions  which  can 
alone  be  framed  respecting  the  ultimate  character  of  cogni- 
tion. Suppose  the  thing  presented  in  consciousness  persists 
unchanged;  then,  as  in  the  absence  of  change  there  is  no 
consciousness,  there  can  be  no  knowledge.  Suppose  there 
follows  something  which  has  no  determinate  relation  what- 
ever to  its  antecedent;  then,  the  change  being  wholly  inde- 
terminate, there  is  no  knowledge,  since  knowledge  is  the 
establishment  in  thought  of  determinate  relations.  Suppose 
lastly,  that  the  succeeding  something  has  a  determinate 
relation  to  that  which  precedes  it;  then  the  implication  is 
that  the  two  are  linked  (if  they  are  not,  any  other  thing  may 
equally  well  follow) ;  and  to  think  of  a  special  thing  (exist- 
ing) as  linked  with  a  special  thing  (about  to  exist)  is  to 
think  of  the  second  as  having  a  speciality  resulting  from  the 
co-operation  of  the  first  and  something  else.  So  that  be  the 
thing  contemplated  in  the  act  of  cognition  a  symbolized 
activity  existing  beyond  the  Mind,  or  be  it  a  past  state  of 
Mind  itself,  that  which  contemplates  it  is  distinct  from  it. 
Hence  were  it  possible  for  the  substance  of  Mind  to  be  pre- 
sent in  any  state  of  Mind,  there  would  still  have  to  be 
answered  the  question — What  is  it  which  then  contemplates 
it  and  knows  it?  That  which  in  the  act  of  knowing  is  affected 
by  the  thing  known,  must  itself  be  the  substance  of  Mind. 
The  substance  of  Mind  escapes  into  some  new  form  in  recog- 
nizing some  form  under  which  it  has  just  existed.  Hence 
could  the  unmodified  substance  of  Mind  be  presented  in 
consciousness,  it  would  still  be  unknowable;  since,  until 
there  had  arisen  something  different  from  it,  the  elements  of 
a  cognition  would  not  exist ;  and  as  this  something  different 
would  necessarily  be  some  state  of  Mind,  we  should  have  the 
substance  of  Mind  known  in  a  state  of  Mind,  which  is  a  con- 
11 


148  THE  INDUCTIONS  OP  PSYCHOLOGY. 

tradiction.  In  brief,  a  thing  cannot  at  the  same  instant  be 
both  subject  and  object  of  thought;  and  yet  the  substance 
of  Mind  must  be  this  before  it  can  be  known. 

Again,  to  know  anything  is  to  distinguish  it  as  such 
or  such — to  class  it  as  of  this  or  that  order.  An  object 
is  said  to  be  but  little  known,  when  it  is  alien  to  objects 
of  which  we  have  had  experience;  and  it  is  said  to  be  well 
known,  when  there  is  great  community  of  attributes  be- 
tween it  and  objects  of  which  we  have  had  experience. 
Hence,  by  implication,  an  object  is  completely  known  when 
this  recognized  community  is  complete;  and  completely 
unknown  when  there  is  no  recognized  community  at  alL 
Manifestly,  then,  the  smallest  conceivable  degree  of  know- 
ledge implies  at  least  two  things  between  which  some  com- 
munity is  recognized.  But  if  so,  how  can  we  know  the  sub- 
stance of  Mind?  To  know  the  substance  of  Mind  is  to  be 
conscious  of  some  community  between  it  and  some  other 
substance.  If,  with  the  Idealist,  we  say  that  there  exists  no 
other  substance;  then,  necessarily,  as  there  is  nothing  with 
which  the  substance  of  Mind  can  be  even  compared,  much 
less  assimilated,  it  remains  unknown.  While,  if  we  hold 
with  the  Realist  that  Being  is  fundamentally  divisible  into 
that  which  is  present  to  us  as  Mind,  and  that  which,  lying 
outside  of  it,  is  not  Mind ;  then,  as  the  proposition  itself  as- 
serts a  difference  and  not  a  likeness,  it  is  equally  clear  that 
Mind  remains  unclassable  and  therefore  unknowable. 

§  60.  From  this  absolute  ignorance  of  the  substance  of 
Mind,  considered  as  the  something  of  which  all  particular 
states  of  Mind  are  modifications,  let  us  now  turn  to  that  par- 
tial knowledge  of  these  particular  states,  as  qualitatively 
characterized,  which  lies  within  our  possible  grasp.  Al- 
though the  individual  sensations  and  emotions,  real  or  ideal, 
of  which  consciousness  is  built  up,  appear  to  be  severally 
simple,  homogeneous,  unanalyzable,  or  of  inscrutable  na- 
tures, yet  they  are  not  so.    There  is  at  least  one  kind  of  feel- 


THE  SUBSTANCE  OF  MIND.  149 

ing  whicli,  as  ordinarily  experienced,  seems  elementary,  that 
is  demonstrably  not  elementary.  And  after  resolving  it 
into  its  proximate  components,  we  can  scarcely  help  sus- 
pecting that  other  apparently-elementary  feelings  are  also 
compound,  and  may  have  proximate  components  like  those 
which  we  can  in  this  one  instance  identify. 

Musical  sound  is  the  name  we  give  to  this  seemingly- 
simple  feeling  which  is  clearly  resolvable  into  simpler  feel- 
ings. Well  known  experiments  prove  that  when  equal 
blows  or  taps  are  made  one  after  another  at  a  rate  not 
exceeding  some  sixteen  per  second,  the  effect  of  each  is 
perceived  as  a  separate  noise;  but  when  the  rapidity  with 
which  the  blows  follow  one  another  exceeds  this,  the  noises 
are  no  longer  identified  in  separate  states  of  consciousness, 
and  there  arises  in  place  of  them  a  continuous  state  of 
consciousness,  called  a  tone.  On  further  increasing  the 
rapidity  of  the  blows,  the  tone  undergoes  the  change  of 
quality  distinguished  as  a  rise  in  pitch;  and  it  continues 
to  rise  in  pitch  as  the  blows  continue  to  increase  in  rapidity, 
until  it  reaches  an  acuteness  beyond  which  it  is  no  longer 
appreciable  as  a  tone.  So  that  out  of  units  of  feeling  of  the 
same  kind,  many  feelings  distinguishable  from  one  another 
in  quality  result,  according  as  the  units  are  more  or  less  in- 
tegrated. This  is  not  all.  The  inquiries  of  Professor 
Helmholtz  have  shown  that  when,  along  with  one  series  of 
these  rapidly-recurring  noises,  there  is  generated  another 
series  in  which  the  noises  are  more  rapid  though  not 
so  loud,  the  effect  is  a  change  in  that  quality  of  the 
tone  known  as  its  timbre.  As  various  musical  instruments 
show  us,  tones  which  are  alike  in  pitch  and  strength  are 
distinguishable  by  their  harshness  or  sweetness,  their  ring- 
ing or  their  liquid  characters;  and  all  their  specific  pecu- 
liarities are  proved  to  arise  from  the  combination  of  one, 
two,  three,  or  more,  supplementary  series  of  recurrent  noises 
with  the  chief  series  of  recurrent  noises.  So  that  while  the 
unlikenesses  of  feeling  known  as  differences  of  pitch  in  tones, 


150  THE  INDDCTIONS  OF  PSYCHOLOGY. 

are  due  to  differences  of  integration  among  the  recurrent 
noises  of  one  series,  the  unlikenesses  of  feeling  known  as 
differences  of  timbre,  are  due  to  the  simultaneous  integration 
with  this  series  of  other  series  having  other  degrees  of  inte- 
gration. And  thus  an  enormous  number  of  qualitatively- 
contrasted  kinds  of  consciousness  that  seem  severally  ele- 
mentary, prove  to  be  composed  of  one  simple  kind  of 
consciousness,  combined  and  re-combined  with  itself  in  mul- 
titudinous ways. 

Can  we  stop  short  here?  If  the  different  sensations 
known  as  sounds  are  built  out  of  a  common  unit,  is  it  not 
to  be  rationally  inferred  that  so  likewise  are  the  different 
sensations  known  as  tastes,  and  the  different  sensations 
knoAvn  as  odours,  and  the  different  sensations  known  as 
colours?  Nay,  shall  we  not  regard  it  as  probable  that  there 
is  a  unit  common  to  all  these  strongly-contrasted  classes  of 
sensations?  If  the  unlikenesses  among  the  sensations  of 
each  class  may  be  due  to  unlikenesses  among  the  modes  of 
aggregation  of  a  unit  of  consciousness  common  to  them 
all ;  so,  too,  may  the  much  greater  unlikenesses  between  the 
sensations  of  each  class  and  those  of  other  classes.  There 
may  be  a  single  primordial  element  of  consciousness,  and 
the  countless  kinds  of  consciousness  may  be  produced  by 
the  compounding  of  this  element  with  itself  and  the  re- 
compounding  of  its  compounds  with  one  another  in  higher 
and  higher  degrees:  so  producing  increased  multiplicity, 
variety,  and  complexity. 

Have  we  any  clue  to  this  primordial  element?  I  think 
we  have.  That  simple  mental  impression  which  proves 
to  be  the  unit  of  composition  of  the  sensation  of  musical 
tone,  is  allied  to  certain  other  simple  mental  impressions  I 
differently  originated.  The  subjective  effect  produced  by  ^ 
a  crack  or  noise  that  has  no  appreciable  duration,  is  little 
else  than  a  nervous  shock.  Though  we  distinguish  such  a 
nervous  shock  as  belonging  to  what  we  call  sounds,  yet  it 
does  not  differ  very  much  from  nervous  shocks  of  other 


THE  SUBSTANCE  OF  MIND.  ISJ 

kinds.  An  electric  discliarge  sent  through  the  body, 
causes  a  feeling  akin  to  that  which  a  sudden  loud  report 
causes.  A  strong  unexpected  impression  made  through  the 
eyes,  as  by  a  flash  of  lightning,  similarly  gives  rise  to  a 
start  or  shock;  and  though  the  feeling  so  named  seems, 
like  the  electric  shock,  to  have  the  body  at  large  for  its 
seat,  and  may  therefore  be  regarded  as  the  correlative 
rather  of  the  efferent  than  of  the  afferent  disturbance,  yet 
on  remembering  the  mental  change  that  results  from  the 
instantaneous  transit  of  an  object  across  the  field  of  vision, 
I  think  it  may  be  perceived  that  the  feeling  accompanying 
the  efferent  disturbance  is  itself  reduced  very  nearly  to  the 
same  form.  The  state  of  consciousness  so  generated  is, 
in  fact,  comparable  in  quality  to  the  initial  state  of  con- 
sciousness caused  by  a  blow  (distinguishing  it  from  the  pain 
or  other  feeling  that  commences  the  instant  after) ;  which 
state  of  consciousness  caused  by  a  blow,  may  be  taken  as 
the  primitive  and  typical  form  of  the  nervous  shock.  The 
fact  that  sudden  brief  disturbances  thus  set  up  by  different 
stimuli  through  different  sets  of  nerves,  cause  feelings 
scarcely  distinguishable  in  quality,  will  not  appear  strange 
when  we  recollect  that  distinguishableness  of  feeling  implies 
appreciable  duration;  and  that  when  the  duration  is  greatly 
abridged,  nothing  more  is  known  than  that  some  mental 
change  has  occurred  and  ceased.  To  have  a  sensation  of 
redness,  to  know  a  tone  as  acute  or  grave,  to  be  conscious 
of  a  taste  as  sweet,  implies  in  each  case  a  considerable  con- 
tinuity of  state.  If  the  state  does  not  last  long  enough  to 
admit  of  its  being  contemplated,  it  cannot  be  classed  as  of 
this  or  that  kind;  and  becomes  a  momentary  modification 
very  similar  to  momentary  modifications  otherwise  caused. 
It  is  possible,  then — may  we  not  even  say  probable — that 
something  of  the  same  order  as  that  which  we  call  a  nervous 
shock  is  the  ultimate  unit  of  consciousness;  and  that  all  the 
unlikenesses  among  our  feelings  result  from  unlike  modes 
of  integration  of  this  ultimate  unit.     I  say  of  the  same 


152  THE  INDUCTIONS  OF  PSYCHOLOGY. 

order,  because  there  are  discernible  differences  among 
nervous  shocks  that  are  differently  caused;  and  the  primi- 
tive nervous  shock  probably  differs  somewhat  from  each  of 
them.  And  I  say  of  the  same  order  for  the  further  reason, 
that  while  we  may  ascribe  to  them  a  general  likeness  in 
nature  we  must  suppose  a  great  unlikeness  in  degree. 
The  nervous  shocks  recognized  as  such,  are  violent — must 
be  violent  before  they  can  be  perceived  amid  the  pro- 
cession of  multitudinous  vivid  feelings  suddenly  interrupted 
by  them.  But  the  rapidly-recurring  nervous  shocks  of 
which  the  different  forms  of  feeling  consist,  we  must  assume 
to  be  of  comparatively  moderate,  or  even  of  very  slight, 
intensity.  Were  our  various  sensations  and  emotions  com- 
posed of  rapidly-recurring  shocks  as  strong  as  those  ordi- 
narily called  shocks,  they  would  be  unbearable :  indeed  life 
would  cease  at  once.  We  must  think  of  them  rather  as 
successive  faint  pulses  of  subjective  change,  each  having 
the  same  quality  as  the  strong  pulse  of  subjective  change 
distinguished  as  a  nervous  shock. 

The  reader  will  at  once  see,  if  he  has  not  already  seen, 
the  complete  congruity  between  this  view  and  the  known 
character  of  nerve-action.  As  pointed  out  in  §  33,  experi- 
ments show  that  the  so-called  nerve-current  is  intermittent 
— consists  of  waves  which  follow  one  another  from  the  place 
where  the  disturbance  arises  to  the  place  where  its  effect  is 
felt.  The  external  stimulus  in  no  case  acts  continuously  on 
the  sentient  centre,  but  sends  to  it  a  series  of  pulses  of 
molecular  motion.  Hence,  in  concluding  that  the  subjective 
effect  or  feeling,  is  composed  of  rapidly-recurring  mental 
shocks,  we  simply  conclude  that  it  corresponds  with  the 
objective  cause — the  rapidly-recurring  shocks  of  molecular 
change.  Our  typical  case  of  musical  sound  well  exhibits 
the  agreement.  We  have  a  single  aerial  wave,  a  single 
movement  of  the  drum  of  the  ear,  a  single  impact  on  the 
expansion  of  the  auditory  nerve,  a  single  wave  propagated 
to  the  auditory  centre,  and  a  single  shock  of  feeling  known 


THE  SUBSTANCE  OP  MIND.  163 

as  a  crack  or  a  report;  and  then,  when  there  is  externally 
generated  a  succession  of  such  aerial  waves,  each  working 
its  individual  physical  effect  on  the  auditory  structures,  and 
its  individual  psychical  effect  as  a  kind  of  shock,  we  see 
that  if  the  recurrent  physical  effects  exceed  a  certain  speed, 
the  recurrent  psychical  effects  are  consolidated  into  a  sensa- 
tion of  tone.  So  that  here  the  nerve  pulses  and  the  pulses 
of  feeling  clearly  answer  to  one  another;  and  it  can  scarcely 
be  doubted  that  they  do  so  throughout.* 

We  must  not  omit  a  further  indirect  evidence  equally 
unlooked  for  and  striking.  A  conceivable  solution  is  af- 
forded by  this  hypothesis  of  two  problems  which,  in  its 
absence,  seem  entirely  insoluble.     How  is  it  possible  for 

*  Though  in  the  cases  of  the  other  sensations,  it  is  equally  certain  that 
the  disturbances  propagated  through  the  afferent  and  centripetal  nerves  are 
intermittent,  yet  we  cannot  in  the  same  way  trace  the  genesis  of  the  suc- 
cessive waves.  A  tolerably  good  clue  to  their  mode  of  genesis,  is,  however, 
furnished  by  the  action  of  light  on  the  retina.  Possibly  it  will  be  antici- 
pated that  I  am  about  to  assign  the  rapidly-recurring  pulses  of  the  etherial 
medium,  as  the  causes  of  pulses  recurring  with  equal  rapidity  in  the  optic 
nerves ;  but  I  am  far  from  intending  to  do  this.  Neither  the  velocities  of 
the  nerve-waves,  nor  the  intervals  between  the  nerve-waves,  would  yield 
the  least  countenance  to  such  an  interpretation  ;  even  were  it  reconcilable 
with  the  principles  of  physics.  Undulating  molecules  of  ether  acting  on 
the  immeasurably-heavier  undulating  molecules  of  matter,  can  work  ap- 
preciable changes  in  them  only  by  accumulation  of  minute  effects.  If 
certain  etherial  undulations  correspond  in  rate  with  the  undulations  of  some 
molecule  of  matter  united  with  others  into  a  compound ;  then  this  molecule 
may,  by  a  long  succession  of  etherial  impacts,  have  its  oscillations  so  in- 
creased in  their  sweep  as  to  cause  detachment  of  it,  and  consequent  de- 
composition of  the  compound  molecule  {Principles  of  Biology,  §  13).  But 
for  the  effects  of  etherial  impacts  to  be  thus  accumulated,  time  is  required ; 
and  appreciable  time  is  experimentally  shown  to  be  taken  by  the  decom- 
positions which  light  effects.  Hence,  then,  a  ray  of  light  falling  on  one  of 
the  sensitive  elements  of  the  retina,  may  be  supposed  to  decompose  now  one 
unstable  molecule  and  now  another,  at  intervals  very  long  as  compared  with 
those  of  the  etherial  undulations,  though  very  short  as  estimated  by  our 
measures ;  and  the  decomposition  of  each  molecule  may  be  supposed  to  send 
along  a  connected  nerve-fibre,  the  wave  of  molecular  change  which,  under 
its  subjective  aspect  as  a  nervous  shock,  becomes  the  unit  of  composition 
of  the  sensation  called  light. 


154  THE  INDUCTIONS  OP  PSYCHOLOGY. 

feelings  so  different  in  quality  as  those  of  heat,  of  taste,  of 
colour,  of  tone,  &e.,  to  arise  in  nervous  centres  closely  allied 
to  one  another  in  composition  and  structure?  And  how,  in 
the  course  of  evolution,  can  there  have  been  gradually 
differentiated  these  widely-unlike  orders,  and  genera,  and 
species,  of  feelings?  Possible  answers  are  at  once  supplied 
if  we  assume  that  diverse  feelings  are  produced  by  diverse 
modes,  and  degrees,  and  complexities,  of  integration  of  the 
alleged  ultimate  unit  of  consciousness.  If  each  wave  of 
molecular  motion  brought  by  a  nerve-fibre  to  a  nerve- 
centre,  has  for  its  correlative  a  shock  or  pulse  of  feeling; 
then  we  can  comprehend  how  distinguishable  differences 
of  feeling  may  arise  from  differences  in  the  rates  of  recur- 
rence of  the  waves,  and  we  can  frame  a  general  idea  of  the 
way  in  which,  by  the  arrival  through  other  fibres,  of  waves 
recurring  at  other  rates,  compound  waves  of  molecular 
motion  may  be  formed,  and  give  rise  to  units  of  compound 
feelings:  which  process  of  compounding  of  waves  and  pro- 
duction of  correspondingly-compounded  feelings,  we  may 
imagine  to  be  carried  on  without  limit,  and  to  produce  any 
amount  of  heterogeneity  of  feelings.  After  recognizing  this 
possibility,  the  visible  likenesses  of  nervous  centres  that  are 
the  seats  of  different  feelings,  cease  to  be  mysterious ;  since 
the  structures  of  these  nervous  centres  need  differ  only  as 
much  as  is  requisite  to  produce  different  combinations  of 
the  waves  of  molecular  motion.  Similarly,  there  disappears 
the  difficulty  of  understanding  how  the  multitudinous  di- 
verse forms  of  feeling  have  been  evolved  from  a  primitive 
simple  sensibility;  since  complications  of  the  molecular  mo- 
tions, and  concomitant  feelings,  must  have  gone  on  pari 
fosau  with  correlative  complications  of  minute  structures, 
organized  little  by  little. 

§  61.  The  nature  of  Mind  as  thus  conceived,  will  be 
elucidated  by  comparing  it  with  the  nature  of  Matter; 
and  the  fact  that  a  parallelism  exists  between  that  which 


THE  SUBSTANCE  OF  MIND.  I55 

chemists  have  established  respecting  Matter  and  that  which 
we  here  suppose  respecting  Mind,  will  help  to  justify  the 
conception. 

Multitudinous  substances  that  seem  to  be  homogeneous 
and  simple,  prove  to  be  really  heterogeneous  and  com- 
pound; and  many  that  appear  wholly  unrelated  are  shown 
by  analysis  to  be  near  akin.  Here  is  a  group  of  them  quite 
different  in  their  apparent  characters,  which  have  an  essen- 
tial component  in  common.  Here  is  another  group  simi- 
larly held  together  by  the  universal  presence  of  some  other 
component.  And  then  these  seemingly-different  substances 
each  characterizing  a  different  group,  turn  out  them- 
selves to  contain  an  element  common  to  the  two.  For 
instance,  there  is  a  large  class  of  salts  formed  by  sulphuric 
acid;  another  large  class  formed  by  nitric  acid;  another 
by  acetic  acid;  and  so  on.  And  these  acids,  along  with 
many  others,  are  alL  discovered  to  have  oxygen  for  their 
active  constituent.  Moreover,  there  is  reason 

to  suspect  that  the  so-called  simple  substances  are  them- 
selves compound;  and  that  there  is  but  one  ultimate  form 
of  Matter,  out  of  which  the  successively-more  complex 
forms  of  Matter  are  built  up.  By  the  different  grouping 
of  units,  and  by  the  combination  of  the  unlike  groups 
each  with  its  own  kind  and  each  with  other  kinds,  it  is 
supposed  that  there  have  been  produced  the  kinds  of  matter 
we  call  elementary;  just  as,  by  further  compositions  simi- 
larly carried  on,  these  produce  further  varieties  and  com- 
plexities. And  this  supposition  the  phenomena  of  allo- 
tropism  go  far  to  justify,  by  showing  us  that  the  same  mass 
of  molecules  assumes  quite  different  properties  when  the 
mode  of  aggregation  is  changed. 

If,  then,  we  see  that  by  unlike  arrangements  of  like  units, 
all  the  forms  of  Matter,  apparently  so  diverse  in  nature, 
may  be  produced-r-if,  even  without  assuming  that  the  so- 
called  elements  are  compound,  we  remember  how  from  a  iew 
of  these  there  may  arise  by  transformation  and  by  combina' 


166  'A^^  INDUCTIONS  OF  PSYCHOLOGY. 

tion  numerous  seemingly-simple  substances,  strongly  con- 
trasted with  their  constituents  and  with  one  another;  we 
shall  the  better  conceive  the  possibility  that  the  multi- 
tudinous forms  of  Mind  known  as  different  feelings,  may  be 
composed  of  simpler  units  of  feeling,  and  even  of  units 
fundamentally  of  one  kind.  We  shall  perceive  that  such 
homogeneous  units  of  feeling  may,  by  integration  in  diverse 
ways,  give  origin  to  different  though  relatively-simple  feel- 
ings; by  combination  of  which  with  one  another  more  com- 
plex and  more  unlike  feelings  may  arise;  and  so  on  con- 
tinuously. 

Here,  indeed,  it  may  be  added  that  something  beyond 
analogy  may  perhaps  exist  between  the  methods  of  material 
and  mental  evolution.  When  we  recall  the  fact  that  mole- 
cules are  never  at  rest,  and  that  by  carrying  their  individual 
rhythmical  motions  into  the  compound  molecules  formed  of 
them,  they  produce  compound  rhythms — when  we  recollect 
the  extreme  complexity  of  the  molecules  of  nervous  matter, 
and  imagine  how  various  and  involved  must  be  the  rhythms 
of  which  they  are  the  seats — when,  further,  we  infer  the 
countless  modifications  of  rhythms  that  must  under  such  con- 
ditions become  possible ;  we  shall  dimly  see  a  fitness  of  mo- 
lecular structure  for  originating,  and  being  affected  by,  the 
diversities  and  complications  of  molecular  pulses  above  de- 
scribed. We  shall  suspect  that  there  may  be  here  a  further 
correspondence  between  a  known  cause  of  physical  hetero- 
geneity and  the  supposed  cause  of  psychical  heterogeneity. 

§  62.  While  reading  the  last  two  sections,  some  will 
perhaps  have  thought  that  they  stand  in  direct  contra- 
diction to  the  section  preceding  them.  After  alleging  that 
the  substance  of  Mind  cannot  be  known,  an  attempt  is 
forthwith  made  to  show  that  Mind  is,  certainly  in  some 
cases  and  probably  in  all,  resolvable  into  nervous  shocks; 
and  that  these  nervous  shocks  answer  to  the  waves  of 
molecular  motion  that  traverse  nerves  and  nerve-centres. 


THE  SUBSTANCE  OF  MIND.  157 

Thus  not  only  is  the  substance  of  Mind  supposed  to  be 
knowable  as  having  this  universal  character,  but  it  is 
closely  assimilated  to,  if  not  identified  with,  nervous 
change. 

The  alarm  is  groundless  however.  The  foregoing  reason- 
ing brings  us  no  nearer  to  a  solution  of  the  final  question. 
Even  could  we  succeed  in  proving  that  Mind  consists  of 
homogeneous  units  of  feeling  of  the  nature  specified,  we 
should  be  unable  to  say  what  Mind  is;  just  as  we  should 
be  unable  to  say  what  Matter  is,  could  we  succeed  in  de- 
composing it  into  those  ultimate  homogeneous  units  of 
which  it  is  not  improbably  composed.  In  the  one  case,  as  in 
the  other,  the  ultimate  unit  must  remain,  for  the  reasons  as- 
signed at  the  outset,  absolutely  unknown.  The  reduction  of 
all  the  more  complex  forms  to  the  simplest  form,  leaves  us 
with  nothing  but  this  simplest  form  as  the  term  out  of 
which  to  frame  thought;  and  thought  cannot  be  framed 
out  of  one  term  only.  Representation  and  re-representation 
of  this  ultimate  unit  of  consciousness  in  terms  of  itself, 
leaves  us  at  last  just  where  we  were  at  first.  And  repre- 
sentation of  it  in  any  other  terms  involves  a  contradiction. 
For  to  think  of  it  as  having  some  assigned  nature,  is  to 
think  of  it  in  some  other  mode  of  consciousness;  in  which 
case  such  other  mode  of  consciousness  cannot  have  this  unit 
of  consciousness  for  its  component,  which  is  contrary  to  the 
hypothesis. 

When  the  two  modes  of  Being  which  we  distinguish  as 
Subject  and  Object,  have  been  severally  reduced  to  their 
lowest  terms,  any  further  comprehension  must  be  an  assimila- 
tion of  these  lowest  terms  to  one  another;  and,  as  we  have 
already  seen,  this  is  negatived  by  the  very  distinction  of  Sub- 
ject and  Object,  which  is  itself  the  consciousness  of  a  differ- 
ence transcending  all  other  differences.  So  far  from  help- 
ing us  to  think  of  them  as  of  one  kind,  analysis  serves  but  to 
render  more  manifest  the  impossibility  of  finding  for  them  a 
common  concept — a  thought  under  which  they  can  be  united. 


X68  THE  INDUCTIONS  OF  PSYCHOLOGY. 

Let  it  be  granted  that  all  existence  distinguished  as  ob- 
jective, may  be  resolved  into  the  existence  of  units  of  one 
kind.  Let  it  be  granted  that  every  species  of  objective 
activity,  may  be  understood  as  due  to  the  rhythmical  mo- 
tions of  such  ultimate  units;  and  that  among  the  objective 
activities  so  understood,  are  the  waves  of  molecular  motion 
propagated  through  nerves  and  nerve-centres.  And  let  it 
further  be  granted  that  all  existence  distinguished  as  sub- 
jective, is  resolvable  into  units  of  consciousness  similar  in 
nature  to  those  which  we  know  as  nervous  shocks;  each  of 
which  is  the  correlative  of  a  rhythmical  motion  of  a  material 
unit,  or  group  of  such  units.  Can  we  then  think  of  the  sub- 
jective and  objective  activities  as  the  same?  Can  the  oscil- 
lation of  a  molecule  be  represented  in  consciousness  side  by 
side  with  a  nervous  shock,  and  the  two  be  recognized  as 
one?  No  effort  enables  us  to  assimilate  them.  That  a  unit 
of  feeling  has  nothing  in  common  with  a  unit  of  motion,  be- 
comes more  than  ever  manifest  when  we  bring  the  two  into 
juxtaposition.  And  the  immediate  verdict  of  consciousness 
thus  given,  might  be  analytically  justified  were  this  a  fit 
place  for  the  needful  analysis.  For  it  might  be  shown  that 
the  conception  of  an  oscillating  molecule  is  built  out  of  many 
units  of  feeling;  and  that  to  identify  it  with  a  nervous  shock 
would  be  to  identify  a  whole  congeries  of  units  with  a  single 
unit. 

§  63.  Here,  indeed,  we  arrive  at  the  barrier  which  needs 
to  be  perpetually  pointed  out ;  alike  to  those  who  seek  mate- 
rialistic explanations  of  mental  phenomena,  and  to  those  who 
are  alarmed  lest  such  explanations  may  be  found.  The  last 
class  prove  by  their  fear,  almost  as  much  as  the  first  prove 
by  their  hope,  that  they  believe  Mind  may  possibly  be  inter- 
preted in  terms  of  Matter;  whereas  many  whom  they  vitu- 
perate as  materialists,  are  profoundly  convinced  that  there 
is  not  the  remotest  possibility  "of  so  interpreting  them. 
For  those  who,  not  deterred  by  foregone  conclusions,  have 


THE  SUBSTANCE  OF  MIND.  159 

pushed  their  analyses  to  the  uttermost,  see  very  clearly 
that  the  concept  we  form  to  ourselves  of  Matter,  is  but  the 
symbol  of  some  form  of  Power  absolutely  and  for  ever  un- 
known to  us;  and  a  symbol  which  we  cannot  suppose  to  be 
like  the  reality  without  involving  ourselves  in  contradictions 
{First Principles^  §  16).  They  also  see  that  the  representa- 
tion of  all  objective  activities  in  terms  of  Motion,  is  but  a  re- 
presentation of  them  and  not  a  knowledge  of  them;  and 
that  we  are  immediately  brought  to  alternative  absurdities 
if  we  assume  the  Power  manifested  to  us  as  Motion,  to  be 
in  itself  that  which  we  conceive  as  Motion  {First  Prin- 
oipleSy  §  17).  When  with  these  conclusions  that  Matter  and 
Motion  as  we  think  them  are  but  symbolic  of  unknowable 
forms  of  existence,  we  join  the  conclusion  lately  reached  that 
Mind  also  is  unknowable,  and  that  the  simplest  form  under 
which  we  can  think  of  its  substance  is  but  a  symbol  of  some- 
thing that  can  never  be  rendered  into  thought ;  we  see  that 
the  whole  question  is  at  last  nothing  more  than  the  question 
whether  these  symbols  should  be  expressed  in  terms  of  those 
or  those  in  terms  of  these — a  question  scarcely  worth  de- 
ciding; since  either  answer  leaves  us  as  completely  outside 
of  the  reality  as  we  were  at  first. 

Nevertheless,  it  may  be  as  well  to  say  here,  once  for  all, 
that  were  we  compelled  to  choose  between  the  alternatives  of 
translating  mental  phenomena  into  physical  phenomena,  or 
of  translating  physical  phenomena  into  mental  phenomena, 
the  latter  alternative  would  seem  the  more  acceptable  of  the 
two.  Mind,  as  kno"\vn  to  the  possessor  of  it,  is  a  circum- 
scribed aggregate  of  activities ;  and  the  cohesion  of  these  ac- 
tivities, one  with  another,  throughout  the  aggregate^  com- 
pels the  postulation  of  a  something  of  which  they  are  the 
activities.  But  the  same  experiences  which  make  him 
aware  of  this  coherent  aggregate  of  mental  activities, 
simultaneously  make  him  aware  of  activities  that  are  not 
included  in  it — outlying  activities  which  become  known  by 
their  effects  on  this  aggregate,  but  which  are  experimentally 


160  THE  INDUCTIONS  OF  PSYCHOLOGY. 

proved  to  be  not  coherent  with  it,  and  to  be  coherent  with 
one  another  {First  Principles,  §§  43,  44).  As,  by  the  defi- 
nition of  them,  these  external  activities  cannot  be  brought 
within  the  aggregate  of  activities  distinguished  as  those  of 
Mind,  they  must  for  ever  remain  to  him  nothing  more  than 
the  unknown  correlatives  of  their  effects  on  this  aggregate ; 
and  can  be  thought  of  only  in  terms  furnished  by  this  aggre- 
gate. Hence,  if  he  regards  his  conceptions  of  these  activities 
lying  beyond  Mind,  as  constituting  knowledge  of  them,  he  is 
deluding  himself:  he  is  but  representing  these  activities  in 
terms  of  Mind,  and  can  never  do  otherwise.  Eventually  he 
is  obliged  to  admit  that  his  ideas  of  Matter  and  Motion, 
merely  symbolic  of  unknowable  realities,  are  complex  states 
of  consciousness  built  out  of  units  of  feeling.  But  if,  after 
admitting  this,  he  persists  in  asking  whether  units  of  feeling 
are  of  the  same  nature  as  the  units  of  force  distinguished 
as  external,  or  whether  the  units  of  force  distinguished  as 
external  are  of  the  same  nature  as  units  of  feeling;  then 
the  reply,  still  substantially  the  same,  is  that  we  may  go 
farther  towards  conceiving  units  of  external  force  to  be 
identical  with  units  of  feeling,  than  we  can  towards  con- 
ceiving units  of  feeling  to  be  identical  with  units  of  external 
force.  Clearly,  if  units  of  external  force  are  regarded  as  ab- 
solutely unknown  and  unknowable,  then  to  translate  units  of 
feeling  into  them  is  to  translate  the  known  into  the  unknown, 
which  is  absurd.  And  if  they  are  what  they  are  supposed  to 
be  by  those  who  identify  them  with  their  symbols,  then  the 
difficulty  of  translating  units  of  feeling  into  them  is  insur- 
mountable: if  Force  as  it  objectively  exists  is  absolutely 
alien  in  nature  from  that  which  exists  subjectively  as 
Feeling,  then  the  transformation  of  Force  into  Feeling 
is  unthinkable.  Either  way,  therefore,  it  is  impossible  to 
interpret  inner  existence  in  terms  of  outer  existence.  But 
if,  on  the  other  hand,  units  of  Force  as  they  exist  ob- 
jectively, are  essentially  the  same  in  nature  with  those  mani- 
fested subjectively  as  units  of  Feeling;  then  a  conceivable 


THE  SUBSTANCE  OP  MIND.  161 

hypothesis  remains  open.  Every  element  of  that  aggregate 
of  activities  constituting  a  consciousness,  is  known  as  be- 
longing to  consciousness  only  by  its  cohesion  with  the 
rest.  Beyond  the  limits  of  this  coherent  aggregate  of 
activities,  exist  activities  quite  independent  of  it,  and 
which  cannot  be  brought  into  it.  We  may  imagine,  then, 
that  by  their  exclusion  from  the  circumscribed  activities 
constituting  consciousness,  these  outer  activities,  though  of 
the  same  intrinsic  nature,  become  antithetically  opposed  in 
aspect.  Being  disconnected  from  consciousness,  or  cut  off 
by  its  limits,  they  are  thereby  rendered  foreign  to  it.  !N^ot 
being  incorporated  with  its  activities,  or  linked  with  these 
as  they  are  with  one  another,  consciousness  cannot,  as  it 
were,  run  through  them ;  and  so  they  come  to  be  figured  as 
unconscious — are  symbolized  as  having  the  nature  called 
material  as  opposed  to  that  called  spiritual.  While,  however, 
it  thus  seems  an  imaginable  possibility  that  units  of  external 
Force  may  be  identical  in  nature  with  units  of  the  force 
known  as  Feeling,  yet  we  cannot  by  so  representing  them  get 
any  nearer  to  a  comprehension  of  external  Force.  For,  as 
already  shown,  supposing  all  forms  of  Mind  to  be  composed 
of  homogeneous  units  of  feeling  variously  aggregated,  the 
resolution  of  them  into  such  units  leaves  us  as  unable  as 
before  to  think  of  the  substance  of  Mind  as  it  exists  in  such 
units;  and  thus,  even  could  we  really  figure  to  ourselves  all 
units  of  external  Force  as  being  essentially  like  units  of 
the  force  known  as  Feeling,  and  as  so  constituting  a  uni- 
versal sentiency,  we  should  be  as  far  as  ever  from  forming 
a  conception  of  that  which  is  universally  sentient. 

Hence  though  of  the  two  it  seems  easier  to  translate  so- 
called  Matter  into  so-called  Spirit,  than  to  translate  so- 
called  Spirit  into  so-called  Matter  (which  latter  is,  indeed, 
wholly  impossible) ;  yet  no  translation  can  carry  us  beyond 
our  symbols.  Such  vague  conceptions  as  loom  before  us 
are  illusions  conjured  up  by  the  wrong  connotations  of  our 
words.    The  expression  "  substance  of  Mind,"  if  we  use  it 


162  THE  INDUCTIONS  OF  PSYCHOLOGY. 

in  any  other  way  than  as  the  x  of  our  equation,  inevitably 
betrays  us  into  errors;  for  we  cannot  think  of  substance 
save  in  terms  that  imply  material  properties.  Our  only 
course  is  constantly  to  recognize  our  symbols  as  symbols 
only;  and  to  rest  content  with  that  duality  of  them  which 
our  constitution  necessitates.  The  Unknowable  as  mani- 
fested to  us  within  the  limits  of  consciousness  in  the  shape 
of  Feeling,  being  no  less  inscrutable  than  The  Unknowable 
as  manifested  beyond  the  limits  of  consciousness  in  other 
shapes,  we  approach  no  nearer  to  understanding  the  last 
by  rendering  it  into  the  first.  The  conditioned  form  under 
which  Being  is  presented  in  the  Subject,  cannot,  any  more 
than  the  conditioned  form  under  which  Being  is  presented 
in  the  Object,  be  the  Unconditioned  Being  conmion  to 
the  two. 


CHAPTER  n. 


THE    COMPOSITION    OF    MXCTD. 


§  64.  In  the  last  chapter  we  incidentally  encroached  on 
the  topic  to  which  this  chapter  is  to  be  devoted.  Certain 
apparently-simple  feelings  were  shown  to  be  compounded  of 
units  of  feeling;  whence  it  was  inferred  that  possibly,  if  not 
probably,  feelings  of  other  classes  are  similarly  compounded. 
And  in  thus  treating  of  the  composition  of  feelings,  we,  by 
implication,  treated  of  the  composition  of  Mind,  of  which 
feelings  are  themselves  components. 

Here,  however,  leaving  speculations  about  the  ultimate 
composition  of  Mind,  we  pass  to  observations  on  its  proxi- 
mate composition.  Accepting  as  really  simple  those  con- 
stituents of  Mind  which  are  not  decomposable  by  introspec- 
tion, we  have  to  consider  what  are  their  fundamental  dis- 
tinctive characters,  and  what  are  the  essential  principles  of 
arrangement  among  them. 

§  65.  The  proximate  components  of  Mind  are  of  two 
broadly-contrasted  kinds — Feelings  and  the  Relations 
between  feelings.  Among  the  members  of  each  group  there 
exist  multitudinous  unlikenesses,  many  of  which  are  ex- 
tremely strong;  but  such  unlikenesses  are  small  compared 
with  those  which  distinguish  members  of  the  one  group 
from  members  of  the  other.  Let  us,  in  the  first  place,  con- 
sider what  are  the  characters  which  all  Feelings  have  in 
13  163 


164  THE  INDUCTIONS  OF  PSYCHOLOGY. 

common,  and  what  are  the  characters  which  all  Relations 
between  feelings  have  in  common. 

Each  feeling,  as  we  here  define  it,  is  any  portion  of  con- 
sciousness which  occupies  a  place  sufficiently  large  to  give  it 
a  perceivable  individuality;  which  has  its  individuality 
marked  off  from  adjacent  portions  of  consciousness  by  quali- 
tative contrasts;  and  which,  when  introspectively  contem- 
plated, appears  to  be  homogeneous.  These  are  the  essentials. 
Obviously  if,  under  introspection,  a  state  of  consciousness  is 
decomposable  into  unlike  parts  that  exist  either  simultane- 
ously or  successively,  it  is  not  one  feeling  but  two  or  more. 
Obviously  if  it  is  indistinguishable  from  an  adjacent  por- 
tion of  consciousness,  it  forms  one  with  that  portion — is  not 
an  individual  feeling  but  part  of  one.  And  obviously  if  it 
does  not  occupy  in  consciousness  an  appreciable  area,  or  an 
appreciable  duration,  it  cannot  be  known  as  a  feeling. 

A  relation  between  feelings  is,  on  the  contrary,  charac- 
terized by  occupying  no  appreciable  part  of  consciousness. 
Take  away  the  terms  it  unites,  and  it  disappears  along 
with  them;  having  no  independent  place — no  indivi- 
duality of  its  own.  It  is  true  that,  under  an  ultimate 
analysis,  what  we  call  a  relation  proves  to  be  itself  a  kind 
of  feeling — the  momentary  feeling  accompanying  the  tran- 
sition from  one  conspicuous  feeling  to  an  adjacent  con- 
spicuous feeling.  And  it  is  true  that,  notwithstanding  its 
extreme  brevity,  its  qualitative  character  is  appreciable ;  for 
relations  are  (as  we  shall  hereafter  see)  distinguishable  from 
one  another  only  by  the  unlikenesses  of  the  feelings  which 
accompany  the  momentary  transitions.  Each  relational 
feeling  may,  in  fact,  be  regarded  as  one  of  those  nervous 
shocks  which  we  suspect  to  be  the  units  of  composition  of 
feelings;  and,  though  instantaneous,  it  is  known  as  of  greater 
or  less  strength  and  as  taking  place  with  greater  or  less 
facility.  But  the  contrast  between  these  relational  feelings 
and  what  we  ordinarily  call  feelings,  is  so  strong  that  we 
must  class  them  apart.    Their  extreme  brevity,  their  small 


THE  COMPOSITION  OF  MIND.  165 

variety,  and  their  dependence  on  the  terms  they  unite,  dif- 
ferentiate them  in  an  unmistakeable  way.* 

Perhaps  it  will  be  well  to  recognize  more  fully  the  truth 
that  this  distinction  cannot  be  absolute.  Besides  admitting 
that,  as  an  element  of  consciousness,  a  relation  is  a  momen- 
tary feeling,  we  must  also  admit  that  just  as  a  relation  can 
have  no  existence  apart  from  the  feelings  which  form  its 
terms,  so  a  feeling  can  exist  only  by  relations  to  other  feel- 
ings which  limit  it  in  space  or  time  or  both.  Strictly 
speaking,  neither  a  feeling  nor  a  relation  is  an  independent 
element  of  consciousness :  there  is  throughout  a  dependence 
such  that  the  appreciable  areas  of  consciousness  occupied  by 
feelings,  can  no  more  possess  individualities  apart  from  the 
relations  which  link  them,  than  these  relations  can  possess 
individualities  apart  from  the  feelings  they  link.  The 
essential  distinction  between  the  two,  then,  appears  to  be 
that  whereas  a  relational  feeling  is  a  portion  of  conscious- 
ness inseparable  into  parts,  a  feeling  ordinarily  so-called, 
is  a  portion  of  consciousness  that  admits  imaginary  division 
into  like  parts  which  are  related  to  one  another  in  sequence 
or  co-existence.  A  feeling  proper  is  either  made  up  of 
like  parts  that  occupy  time,  or  it  is  made  up  of  like  parts 
that  occupy  space,  or  both.  In  any  case,  a  feeling  proper 
is  an  aggregate  of  related  like  parts,  while  a  relational  feel- 
ing is  undecomposable.  And  this  is  exactly  the  contrast 
between  the  two  which  must  result  if,  as  we  have  inferred, 
feelings  are  composed  of  units  of  feeling,  or  shocks. 

§  66.  Simple  feelings  as  above  defined,  are  of  various 
kinds.     To  say  anything  here  about  the  classification  of 

•  It  will  perhaps  be  objected  that  some  relations,  as  those  between  things 
which  are  distant  in  Space  or  in  Time,  occupy  distinguishable  portions  of 
consciousness.  These,  however,  are  not  the  simple  relations  between 
adjacent  feelings  which  we  are  here  dealing  with.  They  are  relations  that 
bridge  over  great  numbers  of  intervening  feelings  and  relations ;  and  come 
into  existence  only  by  quick  transitions  through  these  intervening  states, 
ending  in  the  consolidation  of  them. 


100  THE  INDUCTIONS  OF  PSYCHOLOGY. 

them,  involves  some  forestalling  of  a  future  chapter.  This 
breach  of  order,  however,  is  unavoidable;  for  until  certain 
provisional  groupings  have  been  made,  further  exposition  is 
scarcely  practicable. 

Limiting  our  attention  to  seemingly-homogeneous  feelings 
as  primarily  experienced,  they  may  be  divided  into  the 
feelings  which  are  centrally  initiated  and  the  feelings  which 
are  peripherally  initiated — emotions  and  sensations.  These 
have  widely  unlike  characters.  Towards  the  close  of  this 
volume  evidence  will  be  found  that  while  the  sensations  are 
relatively  simple,  the  emotions,  though  seeming  to  be  sim- 
ple are  extremely  compound;  and  that  a  marked  contrast 
of  character  between  them  hence  results.  But  without 
referring  to  any  essential  unlikeness  of  composition,  we  shall 
shortly  see  that  between  the  centrally-initiated  feelings  and 
the  peripherally-initiated  feelings,  fundamental  distinctions 
may  be  established  by  introspective  comparison. 

A  subdivision  has  to  be  made.  The  peripherally-initiated 
feelings,  or  sensations,  may  be  grouped  into  those  which, 
caused  by  disturbances  at  the  ends  of  nerves  distributed  on 
the  outer  surface,  are  taken  to  imply  outer  agencies,  and 
those  which,  caused  by  disturbances  at  the  ends  of  nerves 
distributed  within  the  body,  are  not  taken  to  imply  outer 
agencies;  which  last,  though  not  peripherally  initiated  in 
the  ordinary  sense,  are  so  in  the  physiological  sense.  But  as 
between  the  exterior  of  the  body  and  its  interior,  there  are 
all  gradations  of  depth,  it  results  that  this  distinction  is  a 
broadly  marked  one,  rather  than  a  sharply  marked  one.  We 
.shall,  however,  find  that  certain  differential  characters  among 
the  sensations  accompany  this  difference  of  distribution  of 
the  nerves  in  which  they  arise;  and  that  they  are  decided 
in  proportion  to  the  relative  superficiality  or  centrality  of 
these  nerves. 

In  contrast  with  this  class  of  primary  or  real  feelings, 
thus  divided  and  subdivided,  has  to  be  set  the  complemen- 
tary class  of  secondary  or  ideal  feelings,  similarly  divided 


THE  COMPOSITION  OF  MIND.  167 

and  subdivided.  Speaking  generally,  the  two  classes  differ 
greatly  in  intensity.  While  the  primary  or  originally-pro- 
duced feelings  are  relatively  vivid,  the  secondary  or  re- 
produced feelings  are  relatively  faint.  It  should  be  added 
that  the  vivid  feelings  are  taken  to  imply  objective  exciting 
agents  then  and  there  acting  on  the  periphery  of  the 
nervous  system;  while  the  faint  feelings,  though  taken  to 
imply  objective  exciting  agents  which  thus  acted  at  a  past 
time,  are  not  taken  to  imply  their  present  action. 

We  are  thus  obliged  to  carry  with  us  a  classification  based 
on  structure  and  a  classification  based  on  function.  The 
division  into  centrally-initiated  feelings,  called  emotions, 
and  peripherally-initiated  feelings,  called  sensations ;  and  the 
subdivision  of  these  last  into  sensations  that  arise  on  the 
exterior  of  the  body  and  sensations  that  arise  in  its  interior; 
respectively  refer  to  differences  among  the  parts  in  action. 
Whereas  the  division  into  vivid  or  real  feelings  and  faint 
or  ideal  feelings,  cutting  across  the  other  divisions  at  right 
angles  as  we  may  say,  refers  to  difference  of  amount  in  the 
actions  of  these  parts.  The  first  classification  has  in  view 
unlikenesses  of  kind  among  the  feelings ;  and  the  second,  a 
marked  unlikeness  of  degree,  common  to  all  the  kinds. 

§  67.  From  the  classes  of  simple  feelings  we  pass  to  the 
classes  of  simple  relations  between  feelings,  respecting  which 
also,  something  must  be  said  before  we  can  proceed.  In 
default  of  an  ultimate  analysis,  which  cannot  be  made  at 
present,  certain  brief  general  statements  must  suffice. 

As  already  said,  the  requisite  to  the  existence  of  a  rela- 
tion is  the  existence  of  two  feelings  between  which  it  is 
the  link.  The  requisite  to  the  existence  of  two  feelings  is 
some  difference.  And  therefore  the  requisite  to  the  exist- 
ence of  a  relation  is  the  occurrence  of  a  change — the  passage 
from  one  apparently-uniform  state  to  another  apparently- 
uniform  state,  implying  the  momentary  shock  produced  by 
the  commencement  of  a  new  state. 


168  THE  INDUCTIONS  OF  PSYCHOLOGY. 

It  follows  that  the  degree  of  the  change  or  shock,  con- 
stituting in  other  words  the  consciousness  of  the  degree  of 
difference  between  the  adjacent  states,  is  the  ultimate  basis 
of  the  distinctions  among  relations.  Hence  the  fundamental 
division  of  them  into  relations  between  feelings  that  are 
equal,  or  those  of  likeness,  (which  however  must  be  divided 
by  some  portion  of  consciousness  that  is  unlike  them),  and 
relations  between  feelings  that  are  unequal,  or  those  of  un- 
likeness.  These  last  fall  into  what  we  may  distinguish  as 
relations  of  descending  intensity  and  relations  of  ascending 
intensity,  according  as  the  transition  is  to  a  greater  or  to  a 
less  amount  of  feeling.  And  they  are  further  distinguish- 
able into  relations  of  quantitative  unlikeness,  or  those  occur- 
ring between  feelings  of  the  same  nature  but  different  in 
degree,  and  relations  of  qualitative  unlikeness,  or  those 
occurring  between  feelings  not  of  the  same  nature. 

Relations  thus  contemplated  simply  as  changes,  and 
grouped  according  to  the  degree  of  change  or  the  kind  of 
change,  severally  belong  to  one  or  other  of  two  great 
categories  which  take  no  account  of  the  terms  as  like  or 
unlike  in  nature  or  amount,  but  which  take  account  only  of 
their  order  of  occurrence,  as  either  simultaneous  or  succes- 
sive. This  fundamental  division  of  relations  into  those  of  co- 
existence and  those  of  sequence,  is,  however,  itself  dependent 
on  the  preceding  division  into  relations  of  equality  between 
feelings  and  relations  of  inequality  between  them.  For 
relations  themselves  have  to  be  classed  as  of  like  or  unlike 
kinds  by  comparing  the  momentary  feelings  that  attend  the 
establishment  of  them,  and  observing  whether  these  are  like 
or  unlike;  and,  as  we  shall  hereafter  see,  the  relations  of 
co-existence  and  sequence  are  distinguished  from  one  another 
only  by  a  process  of  this  kind. 

§  6B.  Having  defined  simple  feelings  and  simple  rela- 
tions, and  having  provisionally  classified  the  leading  kinds 
of  each,  we  may  now  go  on  to  observe  how  Mind  is  made 


THE  COMPOSITION  OF  MIND.     ^  169 

up  of  these  elements,  and  how  different  portions  of  it  are 
characterized  by  different  modes  of  combination  of  them. 

Tracts  of  consciousness  formed  of  feehngs  that  are  cen- 
trally initiated,  are  widely  unlike  tracts  of  consciousness 
formed  of  feelings  that  are  peripherally  initiated ;  and  of  the 
tracts  of  consciousness  formed  of  peripherally-initiated  feel- 
ings, those  parts  occupied  by  feelings  that  take  their  rise 
in  the  interior  of  the  body  are  widely  unlike  those  parts 
occupied  by  feelings  that  take  their  rise  on  the  exterior  of 
the  body.  The  marked  unlikenesses  are  in  both  cases  due  to 
the  greater  or  smaller  proportions  of  the  relational  elements 
that  are  present.  Whereas  among  centrally-initiated  feel- 
ings, the  mutual  limitations,  both  simultaneous  and  suc- 
cessive, are  vague  and  far  between;  and  whereas  among 
peripherally-initiated  feelings  caused  by  internal  disturb- 
ances, some  are  extremely  indefinite,  and  few  or  none 
definite  in  a  high  degree;  feelings  caused  by  external  dis- 
turbances are  mostly  related  quite  clearly,  alike  by  co- 
existence and  sequence,  and  among  the  highest  of  them  the 
mutual  limitations  in  space  or  time  or  both,  are  extremely 
sharp.  These  broad  contrasts,  dependent  on  the  extent 
to  which  the  elements  of  feeling  are  compounded  with  the 
elements  of  relation,  cannot  be  understood,  and  their  import- 
ance perceived,  without  illustrations.  We  will  begin  with 
those  parts  of  Mind  distinguished  by  predominance  of  the 
relational  elements. 

Eemembering  that  the  lenses  of  the  eye  form  a  non- 
sentient  optical  apparatus  that  casts  images  on  the  retina, 
we  may  fairly  say  that  the  retina  is  brought  more 
directly  into  contact  with  the  external  agent  acting  on  it 
than  is  any  other  peripheral  expansion  of  the  nervous 
system.  And  it  is  in  the  tracts  of  conscioiisness  produced 
by  the  various  lights  reflected  from  objects  around  and 
concentrated  on  the  retina,  that  we  find  the  elements  of 
feeling  most  intimately  woven  up  with  the  elements  of 
relation.    The  multitudinous  states  of  consciousness  yielded 


170  THE  INDUCTIONS  OF  PSYCHOLOGY. 

by  vision,  are  above  all  others  sharp  in  their  mutual  limi- 
tations: the  differences  that  occur  between  adjacent  ones 
are  extremely  definite.  It  is  further  to  be  noted  that  the 
relational  element  is  here  dominant  under  both  of  its  funda- 
mental forms.  Some  of  the  feelings  simultaneously  limit  one 
another  with  great  distinctness,  and  some  of  them  with  equal 
distinctness  successively  limit  one  another.  The 

feelings  caused  by  actions  on  the  general  surface  of  the 
body  are  also  marked  off  clearly,  though  by  no  means  so 
clearly  as  those  which  arise  in  the  retina.  Sensations  of 
touch  initiated  at  points  on  the  skin  very  near  one  another, 
form  parts  of  consciousness  that  are  separate  though  adja- 
cent; and  these  are  distinguishable  not  only  as  co-existing 
in  close  proximity,  but  also  as  distinct  from  kindred  sensa- 
tions immediately  preceding  or  immediately  succeeding 
them.  Moreover  the  definiteness  of  their  mutual  limita- 
tions, in  space  if  not  in  time,  is  greatest  among  the  sensa- 
tions of  touch  proceeding  from  parts  of  the  surface  which 
have,  in  a  sense,  the  greatest  externality — the  parts  which, 
Kke  the  tips  of  the  fingers  and  the  tip  of  the  tongue, 
have  the  most  frequent  and  varied  converse  with  outer 
objects.*  Next  in  the  definiteness  of  their  mutual 

limitations  come  the  auditory  feelings.  Among  such  of 
these  as  occur  together,  the  relations  are  marked  with 
imperfect  clearness.  Received  through  uncultivated  ears, 
only  a  few  simultaneous  sounds  are  vaguely  separable  in 
consciousness;  though  received  through  the  ears  of  a 
musician,  many  such  sounds  may  be  distinguished  and 
identified.  But  among  successive  sounds  the  relational 
components  of  mind  are  conspicuous.  Differences  between 
tones  that  follow  one  another,  even  very  rapidly,  are  clearly 

•  The  tonprue  is  a  much  more  active  tactual  organ  than  at  first  appears. 
The  mechanical  impressions  it  receives  are  not  limited  to  those  given  by 
the  food  which  it  manages  during  mastication  ;  but  at  other  times  it  is 
perpetually  exploring  the  inner  surfaces  of  the  teeth,  which  are  to  it  ex- 
ternal bodies. 


THE  COMPOSITION  OF  MIND.  171 

perceived.  But  the  demarcations  are  less  decided  tlian 
those  between  contrasted  sensations  in  the  field  of 
vision.  Passing  to  the  sensations  of  taste,  we 

see  that  these,  less  external  in  their  origin  (for  it  is  not  in 
the  tip  of  the  tongue,  but  over  its  hinder  part  and  the  back 
of  the  palate,  that  the  gustatory  nerves  are  distributed),  are 
comparatively  indefinite  in  their  relations.  Such  distinc- 
tions as  may  be  perceived  between  tastes  that  co-exist  are 
comparatively  vague,  and  can  be  extended  to  but  two  or 
three.  Similarly,  the  beginnings  and  ends  of  successive 
tastes  are  far  less  sharp  than  the  beginnings  and  ends  of  the 
visual  impressions  we  receive  at  every  glance;  nor  can  suc- 
cessive tastes  be  distinguished  with  anything  like  the  same 
rapidity  as  successive  tones.  Even  more  unde- 

cided are  the  mutual  limitations  among  sensations  of 
smell,  which,  like  the  last,  originate  at  a  considerable  dis- 
tance from  the  surface  (for  the  nose  is  not  the  seat  of  smell : 
the  olfactory  chamber,  with  which  the  nostrils  communicate, 
is  seated  high  up  between  the  eyes).  Of  simultaneous 
smells  the  discrimination  is  very  vague;  and  probably  not 
more  than  three  can  be  separately  identified.  Of  smells 
that  follow  one  another,  it  is  manifest  that  they  begin  and 
end  indefinitely,  and  that  they  cannot  be  experienced  in 
rapid  succession. 

We  come  now  to  the  peripherally-initiated  feelings  set 
up  by  internal  disturbances.  Among  these  the  most  super- 
ficial in  origin  and  most  relational  as  they  exist  in  con- 
sciousness, are  the  sensations  of  muscular  tension.  Though, 
except  when  making  vigorous  efforts,  these  are  but  feeble; 
though  such  as  are  present  together  mutually  limit  one 
another  in  a  very  vague  way;  and  though  their  beginnings 
and  ends  arc  lj  blurred  that  a  series  of  them  is  but  indis- 
tinctly separable  into  parts;  yet  they  are  juxtaposed  and 
contrasted  to  the  extent  implied  by  discriminations  and 
recognitions  of  them — discriminations  and  recognitions  so 
partial,  however,  as  frequently  to  require  indirect  verifica- 


172  THE  INDUCTIONS  OF  PSYCHOLOGY. 

tions.  It  should  be  added  that  the  relations  among  muscular 
feelings  are  variable  in  abundance  and  distinctness.  They 
are  most  conspicuous  when  the  feelings  come  from  muscles 
that  are  small,  and  in  perpetual  action,  as  those  which  move 
the  eyes,  the  fingers,  and  the  vocal  organs;  and  least  con- 
spicuous when  the  feelings  come  from  muscles  that  are  large 
or  centrally  seated,  or  both,  as  those  of  the  legs  and  of  the 
trunk.  Passing  over  abnormal  feelings  of  pain  and 

discomfort  due  to  disturbances  of  nerves  distributed  within 
the  limbs  and  body,  among  which  the  small  proportion  of 
the  relational  element  is  manifest,  it  will  suffice  if  we  come 
at  once  to  the  feelings  originating  in  parts  that  are  remotest 
from  the  external  world,  and  which,  as  least  relational,  are 
most  distinguished  from  those  we  set  out  with.  Hunger  is 
extremely  vague  in  its  beginning  and  end.  Commencing  un- 
obtrusively and  ceasing  gradually,  it  is  utterly  unlike  those 
feelings  which,  closely  contiguous  in  time,  make  one  another 
distinct  by  mutual  limitation.  Neither  is  it  appreciably 
marked  out  by  co-existing  feelings:  its  position  among 
simultaneous  states  of  consciousness  is  indeterminate.  And 
this  indefiniteness  of  relation,  both  in  space  and  time,  cha- 
racterizes other  visceral  feelings,  both  normal  and  abnormal. 
Of  the  centrally-initiated  feelings,  or  emotions,  much  the 
same  has  to  be  said  as  of  the  last.  Their  beginnings  and 
endings  in  time  are  comparatively  indefinite,  and  they  have 
no  definite  localizations  in  space.  That  is  to  say,  they  are 
not  limited  by  preceding  and  succeeding  states  of  conscious- 
ness with  any  precision;  and  no  identifiable  bounds  are  put 
to  them  by  states  of  consciousness  that  co-exist.  Here,  then, 
the  relational  element  of  mind  is  extremely  inconspicuous. 
The  sequences  among  emotions  that  can  occur  in  a  given 
period,  are  comparatively  few  and  indeterminate;  and  be- 
tween such  two  or  three  emotions  as  can  co-exist  it  is  impossi-- 
ble  to  distinguish  in  more  than  a  vague  way. 

§  69.  Further  and  equally-important  distinctions  obtain 


THE  COMPOSITION  OF  MIND.  173 

between  the  tracts  of  consciousness  thus  broadly  contrasted, 
and  they  are  similarly  caused.  Presence  of  the  relational 
elements,  seen  in  the  mutual  limitations  of  feelings,  simul- 
taneous and  successive,  is  accompanied  by  the  mutual  cohe- 
sion of  feelings;  and  absence  of  the  relational  elements, 
seen  in  the  indeterminate  boundaries  of  feelings  in  space 
and  time,  is  accompanied  by  their  incoherence.  Let  us 
re-observe  the  tracts  of  consciousness  above  compared. 

The  sharply-defined  patches  of  colour  that  occur  together 
in  a  visual  impression,  are  indissolubly  united — held  rigidly 
in  juxtaposition.  And  successive  visual  feelings,  such  as  are 
produced  by  transferring  the  gaze  from  one  object  to 
another,  have  a  strength  of  connection  that  gives  a  fixed 
consciousness  of  their  order.  Thus  the  visual  feelings, 
above  all  others  distinguished  by  the  sharpness  of  their 
mutual  limitations,  are  absolutely  coherent  in  space  and 
very  coherent  in  time.  Between  sensations  of 

touch  given  by  an  object  grasped,  the  cohesion  is  not  so 
great.  Though  the  two  feelings  produced  by  two  points 
felt  simultaneously  by  a  finger,  hold  together  so  that 
they  cannot  be  removed  far  from  one  another  in  conscious- 
ness ;  yet  the  bond  uniting  them  has  much  less  rigidity  than 
the  bond  uniting  the  visual  feelings  produced  by  the  two 
points;  and  when  the  feelings  are  more  than  two,  their  con- 
nections in  consciousness  are  loose  enough  to  permit  of 
much  variation  in  the  conception  of  their  relative  positions. 
Still  the  strength  of  links  between  co-existing  feelings  of 
touch  is  considerable;  as  is  also  that  between  successive 
feelings  of  the  same  kind.  Among  the  simultaneous 

feelings  caused  by  simultaneous  sounds,  especially  if  they  are 
not  in  harmony,  the  defect  of  cohesion  is  as  marked  as  the 
defect  of  mutual  limitation.  But  among  the  successive  feel- 
ings produced  by  successive  sounds,  we  find  that  along  with 
distinct  mutual  limitations  there  go  decided  mutual  cohe- 
sions. Sequent  notes,  or  articulations,  cling  together  with 
tenacity.  Much  less  clearly  bounded  by  one 


1Y4  THE  INDUCTIONS  OF  PSYCHOLOGY. 

another  as  are  tastes,  simultaneous  and  successive,  they  are 
also  comparatively  incoherent.  Among  co-existent  tastes 
there  are  no  connections  like  those  between  co-existent 
visual  feelings,  or  even  like  those  between  the  sounds  pro- 
duced at  the  same  instant  by  a  band;  and  tastes  do  not  hold 
together  in  sequence  as  do  the  tones  of  cadence.  Of 

smells  the  like  is  true.  Along  with  vagueness  in  the  bound- 
ing of  one  by  another  there  goes  but  a  feeble  linking  together. 

The  feelings  accompanying  muscular  actions  have  cohe- 
sions that  are  hidden  in  much  the  same  way  as  are  their 
limitations.  The  difficulty  of  observing  the  mutual  limita- 
tions of  muscular  feelings,  is  due  to  the  fact  that  each  muscle, 
or  set  of  muscles,  passes  from  a  state  of  rest  to  a  state  of 
action  or  from  a  state  of  action  to  a  state  of  rest,  through 
gradations  that  occupy  an  appreciable  time;  and  that,  con- 
sequently, the  accompanying  feeling,  instead  of  beginning 
and  ending  strongly,  shades  off  at  both  extremes.  Being 
thus  weak  at  the  places  where  they  are  contiguous,  these  feel- 
ings are  incapable  of  strong  cohesions.  Indeed,  if  we  except 
those  which  accompany  great  efforts,  we  may  say  that  they 
are  altogether  so  faint  compared  with  most  others  that  their 
relations,  both  in  kind  and  order,  are  necessarily  incon- 
spicuous. Their  cohesions  are  in  a  great  degree  those  of 
automatic  nervous  acts;  and  are  by  so  much  the  less  the 
cohesions  of  conscious  states.  Those  very  vague 

feelings  which  have  their  seats  in  the  viscera,  may,  as  before, 
be  exemplified  by  hunger.  Here  where  we  reach  such  ex- 
treme indefiniteness  of  limitation,  both  in  space  and  time,  we 
reach  an  extreme  want  of  cohesion.  Hunger  does  not  sud- 
denly follow  some  other  into  consciousness;  nor  is  it  sud- 
denly followed  by  some  other.  Neither  is  there  any  simul- 
taneous feeling  to  which  it  clings.  The  relational  element 
of  Mind  is  almost  absent;  holding  only  in  a  feeble  degree 
with  some  tastes  and  smells. 

Lastly,  among  the  centrally-initiated  feelings,  or  emotions, 
the  same  connection  of  characters  occurs.    When  emotions 


THE  COMPOSITION  OF  MIND.  175 

co-exist,  they  can  scarcely  be  said  to  hold  together:  the 
bond  between  them  is  so  feeble,  that  each  may  disappear 
without  affecting  the  others.  Between  sequent  emotions  the 
links  have  no  appreciable  strength:  no  one  is  attached  to 
another  in  such  way  as  to  produce  constancy  of  succession. 
And  though  between  emotions  and  certain  more  definite 
feelings  which  precede  them,  there  are  strong  connections, 
yet  these  connections  are  not  between  emotions  and  single 
antecedent  feelings,  but  between  emotions  and  large  groups 
of  antecedent  feelings;  and  even  this  cohesion,  very  vari- 
able in  its  strength,  may  entirely  fail. 

§  70.  A  further  trait  in  the  composition  of  Mind,  de- 
pendent on  these  correlated  traits,  may  next  be  set 
down.  We  have  seen  that  tracts  of  consciousness  formed 
of  feelings  produced  by  external  disturbances,  are  mostly 
distinguished  by  predominance  of  the  relational  element, 
involving  clearness  of  mutual  limitation  and  strength  of 
cohesion  among  the  component  feelings;  and  we  have  seen 
that,  contrariwise,  the  feelings  produced  by  internal  dis- 
turbances, peripheral  and  central,  are  mostly  distinguished 
by  comparative  want  of  the  relational  element,  involving 
proportionate  defect  of  mutual  limitation  and  cohesion.  We 
have  now  to  observe  that  the  tracts  of  consciousness  thus 
broadly  contrasted,  are,  by  consequence,  broadly  contrasted 
in  the  respect  that,  in  the  one  case,  the  component  feelings 
can  unite  into  coherent  and  well-defined  clusters,  while,  in 
the  other  case,  they  cannot  so  unite. 

The  state  of  consciousness  produced  by  an  object  seen,  is 
(3omposed  of  sharply-outlined  lights,  shades,  and  colours, 
and  the  co-existent  feelings  and  relations  entering  into  one 
of  these  groups  form  an  indissoluble  whole.  To  a  consider- 
able degree,  successive  visual  feelings  cling  together  in 
defined  groups.  As  most  of  them  are  caused  by  moving 
objects  more  or  less  complex,  it  is  difficult  to  trace  this  clus- 
tering of  them  in  sequence  apart  from  their  clustering  in 


176  THE  INDUCTIONS  OP  PSYCHOLOGY. 

co-existence.  But  if  we  take  the  case  of  a  bird  that 
suddenly  flies  past  close  to  a  window  out  of  which  we  are 
looking,  it  is  manifest  that  the  successive  feelings  form  a 
consciousness  of  its  line  of  movement  so  defined  and  coher- 
ent that  we  know,  without  having  moved  the  eyes,  what  was 
its  exact  course.  The  clustering  of  auditory  feelings, 

comparatively  feeble  among  those  occurring  simultaneously, 
is  comparatively  strong  among  those  occurring  successively. 
Hence  the  consolidated  groups  of  sounds  which  we  know  in 
consciousness  as  words.  Hence  the  chains  of  notes  which 
we  remember  as  musical  phrases.  The  clustering  of 

tactual  feelings  in  relations  of  co-existence,  though  by  no 
means  so  decided  as  the  clustering  of  co-existent  visual  feel- 
ings, either  in  the  extent  or  complexity  of  the  clusters  or  the 
firmness  with  which  their  components  are  united,  is  never- 
theless considerable.  When  the  hand  is  laid  on  some  small 
object,  as  a  key,  a  number  of  impressions  may  be  dis- 
tinguished as  separate  though  near  one  another;  but  while 
their  mutual  relations  are  so  far  fixed  that  approximate 
limits  within  which  they  exist  are  known,  they  do  not 
constitute  anything  like  such  a  fixed  and  defined  group  as 
those  given  by  vision  of  the  key.  This  imperfect  clustering 
in  co-existence  is  accompanied  by  imperfect  clustering  in 
sequence.  The  successive  feelings  produced  by  a  fly 
creeping  over  the  hand,  hold  together  strongly  enough  and 
definitely  enough  to  constitute  a  consciousness  of  its  general 
movement  as  being  towards  the  wrist  or  from  the  wrist, 
across  from  right  to  left  or  from  left  to  right;  but  they  do 
not  form  a  consciousness  of  its  exact  course.  Tastes 

unite  only  into  very  simple  and  incoherent  clusters  in  co- 
existence; while  in  sequence  they  scarcely  unite  at  all. 
And  the  like  is  true  of  smells. 

Such  capability  of  clustering  as  is  displayed  by  the  peri- 
pherally-initiated feelings  caused  by  internal  disturbances, 
occurs  among  those  accompanying  the  movements  of 
muscles.     But,  along  with  the  comparative  vagueness  of 


I  THE  COMPOSITION  OF  MIND.  177 

limitation  and  want  of  strong  cohesion  which  characterize 
these  feelings,  there  goes  a  comparative  indistinctness  of  the 
clusters.  Though  the  nervous  acts  of  which  muscular 
motions  are  results,  combine  into  groups  with  much  pre- 
cision, yet  the  combination  of  them,  at  first  feeble,  becomes 
strong  only  by  repetition.  And  as  the  repetition  which 
makes  the  combination  strong,  makes  it  to  the  same  extent 
automatic,  the  concomitant  feelings  become  less  and  less 
distinct,  and  fade  from  consciousness  as  fast  as  they  unite. 
How,  in  muscular  acts,  complete  clustering  and  unconscious- 
ness go  together,  is  seen  in  the  fact  that  consciousness  im- 
pedes clustered  muscular  acts.  After  having  many  times 
gone  through  the  series  of  compound  movements  required, 
it  is  possible  to  walk  across  the  room  in  the  dark  and  lay 
hold  of  the  handle  of  the  door — so  long,  that  is,  as  the 
movements  are  gone  through  unthinkingly.  If  they  are 
consciously  made,  failure  is  almost  certain.  Of 

the  further  class  of  feelings  initiated  within  the  body, 
including  appetites,  pains,  &c.,  it  is  scarcely  needful  to  say 
that  there  is  among  them  no  formation  of  coherent  groups. 
Their  great  indefiniteness  of  limitation  and  accompanying 
want  of  cohesion,  forbid  unions  of  them,  either  simultaneous 
or  successive. 

Obviously  the  emotions  are  characterized  by  a  like  want 
of  combining  power.  A  confused  and  changing  chaos  is 
produced  by  any  of  them  which  co-exist.  In  fact,  the  ab- 
sence among  them  of  capacity  for  uniting,  is  as  marked 
as  its  presence  among  those  visual  feeling  with  which  we 
set  out. 

§  Yl.  We  come  now  to  more  complex  manifestations  of 
these  general  contrasts.  In  tracts  of  consciousness  where 
the  relational  element  predominates,  and  where  the  clus- 
tering of  feelings  is  consequently  decided,  the  clusters 
themselves  enter  into  relations  one  with  another.  Grouped 
feelings,   together  with  the  relations  uniting  them,   are 


178  THE  INDUCTIONS  OF  PSYCHOLOGY. 

fused  into  wholes  which,  comporting  themselves  as  single 
feelings  do,  combine  with  other  such  consolidated  groups 
in  definite  relations;  and  even  groups  of  groups,  similarly 
fused,  become  in  like  manner  limited  by,  and  coherent  with, 
other  groups  of  groups.  Conversely,  in  tracts  of  conscious- 
ness where  the  relations  are  few  and  vague,  nothing  of  the 
kind  takes  place. 

It  is  among  the  visual  feelings,  above  all  others  multi- 
tudinous, definite,  and  coherent  in  their  relations,  that  this 
compound  clustering  is  carried  to  the  greatest  extent. 
Along  with  the  ability  to  form  that  complex  consciousness 
of  lights,  shades,  and  colours,  joined  in  relative  positions, 
which  constitute  a  man  as  present  to  sight,  there  goes  the 
ability  to  form  a  consciousness  of  two  men  in  a  definite  and 
coherent  relation  of  position — there  goes  the  ability  to  form 
a  consciousness  of  a  crowd  of  such  men;  nay,  two  or  more 
such  crowds  may  be  mentally  combined.  The  aggregate  of 
definitely-related  visual  feelings  known  as  a  house,  itself 
aggregates  with  others  such  to  form  the  consciousness  of  a 
street,  and  the  streets  to  form  the  consciousness  of  a 
town.  Though  the  compound  clustering  of  visual  feelings 
in  sequence  is  not  so  distinct  or  so  strong,  it  is  still  very 
marked.  Numerous  complicated  images  produced  by  objects 
seen  in  succession,  hang  together  in  consciousness  with  con- 
siderable tenacity.  There  is  little,  if  any,  cluster- 
ing of  clusters  among  the  simultaneous  auditory  feelings. 
But  among  the  successive  auditory  feelings  there  are 
definite  and  coherent  combinations  of  groups  with  groups. 
The  fused  set  of  sounds  we  call  a  word,  unites  with  many 
others  such  into  a  sentence.  In  some  minds  these  clusters 
of  clusters  of  successive  sounds  again  cluster  very  definitely 
and  coherently:  many  successive  sentences  are,  as  we 
say,  accurately  remembered.  And  similarly,  musical 
phrases  will  cling  together  into  a  long  and  elaborate 
melody.  Among  the  tactual  feelings  this  com- 
pound clustering  is  scarcely  traceable,  either  in  space  or 


THE  COMPOSITION  OP  MIND.  179 

time;  and  there  is  not  the  remotest  approach  to  it  in  the 
olfactory  and  gustatory  feelings. 

For  form's  sake  it  is  needful  to  say  that  these  higher 
degrees  of  mental  composition  are  entirely  wanting  among 
the  internally-initiated  feelings.  Only  among  those  which 
accompany  muscular  motion  is  there  any  approach  to  it; 
and  here  the  compound  clustering,  like  the  simple  cluster- 
ing, entails  progressing  unconsciousness. 

§  Y2.  One  more  kindred  trait  of  composition  must  be  set 
down.  Thus  far  we  have  observed  only  the  degrees  of  mu- 
tual limitation,  of  cohesion,  and  of  complex  combining  pow- 
er, among  feelings  within  each  order.  It  remains  to  observe 
the  extent  to  which  feelings  of  one  order  enter  into  rela- 
tions with  those  of  another,  and  the  consequent  amounts 
of  their  mutual  limitations  and  of  their  combining  powers. 
To  trace  out  these  at  all  fully  would  carry  us  into  unman- 
ageable detail.    We  must  confine  ourselves  to  leading  facts. 

Feelings  of  different  orders  do  not  limit  one  another 
as  clearly  as  feelings  of  the  same  order  do.  The  clus- 
tered colours  produced  by  an  object  at  which  we  look  are 
but  little  interfered  with  by  a  sound:  the  sound  does  not 
put  any  appreciable  boundary  to  them  in  consciousness,  but 
serves  merely  to  diminish  their  dominance  in  consciousness, 
l^either  the  combined  noises  which  make  up  a  conversation 
at  table,  nor  the  impressions  received  through  the  eyes  from 
the  dishes  on  the  table,  are  excluded  from  the  mind  by  the 
accompanying  tactual  feelings  and  tastes  and  smells,  as 
much  as  colours  are  excluded  by  colours,  sounds  by  sounds, 
tastes  by  tastes,  or  one  tactual  feeling  by  another.  Of 
sensations  arising  within  the  body,  and  still  more  of 
emotions,  it  may  be  said  that,  unless  intense,  they  disturb 
but  slightly  the  sensations  otherwise  arising.  It  would 
almost  seem  as  though  a  sensation  of  colour,  a  sensation  of 
sound,  and  a  pleasurable  emotion  produced  by  the  sound, 

admit  of  being  superposed  in  consciousness  with  but  little 
13 


180  THE  INDUCTIONS  OF  PSYCHOLOGY. 

mutual  obscuration.  Doubtless  in  most  cases  two  simple 
feelings,  or  two  clustered  feelings  of  different  orders,  put 
bounds  to  one  another  in  time  if  not  in  space:  there  is  an 
extremely  rapid  extrusion  of  each  by  the  other  rather  than 
a  continuous  presence  of  either.  But  it  is  manifest  that 
these  alternating  extrusions,  partial  or  complete,  by  feelings 
of  different  orders,  are  less  distinct  than  the  extrusion  of 
one  another  by  feelings  of  the  same  order. 

It  is  a  correlative  truth  that  feelings  of  different  orders 
cohere  with  one  another  less  strongly  than  do  feelings  of 
the  same  order.  The  impressions  which  make  up  the  visual 
consciousness  of  an  object,  hang  together  more  firmly  than 
the  group  of  them  does  with  the  group  of  sounds  making  up 
the  name  of  the  object.  The  notes  composing  a  melody 
have  a  stronger  tendency  to  drag  one  another  into  conscious- 
ness than  any  one,  or  all  of  them,  have  to  drag  into  con- 
sciousness the  sights  along  with  which  they  occurred :  these 
last  may  or  may  not  cohere  with  them ;  but  the  following  of 
one  note  by  the  next  is  often  difficult  to  prevent.  Simi- 
larly, though  there  is  considerable  cohesion  between  the 
visual  sensations  produced  by  an  orange  and  the  taste  or 
smell  of  the  orange,  yet  it  is  quite  usual  to  have  a  visual 
consciousness  of  an  orange  without  its  taste  or  its  smell 
arising  in  consciousness;  while  it  is  scarcely  possible  to  have 
before  the  mind  one  of  its  apparent  characters  unaccom- 
panied by  other  apparent  characters. 

A  further  fact  of  moment  must  be  added.  The  feelings 
of  different  orders  which  enter  into  definite  relations  and 
cohere  most  strongly,  are  those  among  which  there  is  a  pre- 
dominance of  the  relational  elements;  and  there  is  an 
especial  facility  of  combination  between  those  feelings  of 
different  orders  which  are  respectively  held  together  by  re- 
lations of  the  same  order.  Thus  the  co-existent  visual  feel- 
ings, most  relational  of  all,  enter  into  very  definite  and 
coherent  relations  with  co-existent  tactual  feelings.  To  the 
group  of  lights  and  shades  an  object  yields  to  the  eyes,  there 


THE  COMPOSITION  OF  MIND.  181 

attaches  itself  very  strongly  the  group  of  impressions  pro- 
duced by  touching  and  grasping  the  object.  N^ext  in  order 
of  strength  are  the  connections  between  sensations  received 
through  the  eyes  and  those  received  through  the  ears;  or 
rather — between  clusters  of  the  one  and  clusters  of  the  other. 
But  though  the  feelings  clustered  in  co-existence  that  form 
the  visual  consciousness  of  anything,  are  linked  with  much 
strength  to  the  feelings  clustered  in  sequence  that  form  the 
consciousness  of  its  name;  yet,  probably  because  the  feelings 
forming  the  one  cluster  not  only  differ  in  kind  from  those 
forming  the  other  but  are  held  together  by  relations  of  a 
different  order,  the  cohesion  of  the  two  clusters  is  not  so 
strong.  As  we  descend  towards  the  unrelational  feelings  we 
find  that  this  combining  power  of  class  with  class  decreases. 
Between  tastes  and  smells  and  certain  visceral  sensations, 
such  as  hunger  and  nausea,  there  is,  indeed,  a  considerable 
aptitude  to  cohere.  But  after  admitting  exceptions,  it  re- 
mains true  on  the  average  that  the  extremely-unrelational 
states  of  consciousness  of  different  orders,  connect  but  feebly 
with  one  another  and  with  the  extremely-relational  states 
of  consciousness. 

§  Y3.  Thus  far  we  have  proceeded  as  though  Mind  were 
composed  entirely  of  the  primary  or  vivid  feelings,  and 
the  relations  among  them;  ignoring  the  secondary  or  faint 
feelings.  Or  if,  as  must  be  admitted,  there  has  been  a  tacit 
recognition  of  these  secondary  feelings  in  parts  of  the 
foregoing  sections  which  deal  with  the  relations  and  co- 
hesions of  feelings  in  sequence  (since  in  a  sequence  of  feel- 
ings those  which  have  passed  have  become  faint,  and  only 
the  one  present  is  vivid);  yet  there  has  been  no  avowed 
recognition  of  them  as  components  of  Mind  different 
from,  though  closely  allied  with,  the  primary  feelings. 
We  must  now  specially  consider  them  and  the  part  they 
play. 

The  cardinal  fact  to  be  noted  as  of  co-ordinate  im- 


182  THE  INDUCTIONS  OF  PSYCHOLOGY. 

portance  witb.  the  facts  above  noted,  is  that  while  each  vivid 
feeling  is  joined  to,  but  distinguished  from,  other  vivid  feel- 
ings, simultaneous  or  successive,  it  is  joined  to,  and  identi- 
fied with,  faint  feelings  that  have  resulted  from  foregoing 
similar  vivid  feelings.  Each  particular  colour,  each  special 
sound,  each  sensation  of  touch,  taste,  or  smell,  is  at  once 
known  as  unlike  other  sensations  that  limit  it  in  space  or 
time,  and  known  as  like  the  faint  forms  of  certain  sensations 
that  have  preceded  it  in  time — unites  itself  with  foregoing 
sensations  from  which  it  does  not  differ  in  quality  but  only 
in  intensity. 

On  this  law  of  composition  depends  the  orderly  struc- 
ture of  Mind.  In  its  absence  there  could  be  nothing  but 
a  perpetual  kaleidoscopic  change  of  feelings — an  ever- 
transforming  present  without  past  or  future.  It  is  because 
of  this  tendency  which  vivid  feelings  have  severally  to 
cohere  with  the  faint  forms  of  all  preceding  feelings  like 
themselves,  that  there  arise  what  we  call  ideas.  A  vivid 
feeling  does  not  by  itself  constitute  a  unit  of  that  aggre- 
gate of  ideas  entitled  knowledge.  Nor  does  a  single  faint 
feeling  constitute  such  a  unit.  But  an  idea,  or  unit  of 
knowledge,  results  when  a  vivid  feeling  is  assimilated  to,  or 
coheres  with,  one  or  more  of  the  faint  feelings  left  by  such 
vivid  feelings  previously  experienced.  From  moment  to 
moment  the  feelings  that  constitute  consciousness  segregate 
— each  becoming  fused  with  the  whole  series  of  others  like 
itself  that  have  gone  before  it;  and  what  we  call  knowing 
each  feeling  as  such  or  such,  is  our  name  for  this  act  of 
segregation. 

The  process  so  carried  on  does  not  stop  with  the  union  of 
each  feeling,  as  it  occurs,  with  the  faint  forms  of  all  pre- 
ceding like  feelings.  Clusters  of  feelings  are  simultaneously 
joined  with  the  faint  forms  of  preceding  like  clusters.  An 
idea  of  an  object  or  act  is  composed  of  groups  of  similar 
and  similarly-related  feelings  that  have  arisen  in  conscious- 
ness from  time  to  time,  and  have  formed  a  consolidated  series 


THE  COMPOSITION  OF  MIND.  183 

of  wMcli  the  members  have  partially  or  completely  lost  their 
individualities. 

This  union  of  present  clustered  feelings  with  past  clus- 
tered feelings  is  carried  to  a  much  greater  degree  of  com- 
plexity. Groups  of  groups  coalesce  with  kindred  groups 
of  groups  that  preceded  them;  and  in  the  higher  types  of 
Mind,  tracts  of  consciousness  of  an  excessively  composite 
character  are  produced  after  the  same  manner. 

To  complete  this  general  conception  it  is  needful  to  say 
that  as  with  feelings,  so  with  the  relations  between  feelings. 
Parted  so  far  as  may  be  from  the  particular  pairs  of  feelings 
and  pairs  of  groups  of  feelings  they  severally  unite,  rela- 
tions themselves  are  perpetually  segregated.  From  mo- 
ment to  moment  relations  are  distinguished  from  one 
another  in  respect  of  the  degrees  of  contrast  between 
their  terms  and  the  kinds  of  contrast  between  their 
terms;  and  each  relation,  while  distinguished  from  various 
concurrent  relations,  is  assimilated  to  previously-experienced 
relations  like  itself.  Thus  result  ideas  of  relations  as 
those  of  strong  contrast  or  weak  contrast,  of  descending 
intensity  or  ascending  intensity,  of  homogeneity  of  kind 
or  heterogeneity  of  kind.  Simultaneously  occurs  a  segre- 
gation of  a  different  species.  Each  relation  of  co-existence 
is  classed  with  other  like  relations  of  co-existence  and 
separated  from  relations  of  co-existence  that  are  unlike 
it;  and  a  kindred  classing  goes  on  among  relations  of 
sequence.  Finally,  by  a  further  segregation,  are  formed 
that  consolidated  abstract  of  relations  of  co-existence  which 
we  know  as  Space,  and  that  consolidated  abstract  of  rela- 
tions of  sequence  which  we  know  as  Time.  This  process, 
here  briefly  indicated  merely  to  show  its  congruity  with  the 
general  process  of  composition,  cannot  be  explained  at 
length:  the  elucidation  must  come  hereafter. 

§  74.  And  now  having  roughly  sketched  the  composi- 
tion of  Mind — having,  to  preserve  clearness  of  outline, 


184  THE  INDUCTIONS  OF  PSYCHOLOGY. 

omitted  details  and  passed  over  minor  qualifications;  let 
me  go  on  to  indicate  the  essential  truth  which  it  is  a  chief 
purpose  of  this  chapter  to  bring  into  view — the  truth  that 
the  method  of  composition  remains  the  same  throughout 
the  entire  fabric  of  Mind,  from  the  formation  of  its  simplest 
feelings  up  to  the  formation  of  those  immense  and  complex 
aggregates  of  feelings  which  characterize  its  highest  deve- 
lopments. 

In  the  last  chapter  we  saw  that  what  is  objectively  a 
wave  of  molecular  change  propagated  through  a  nerve- 
centre,  is  subjectively  a  unit  of  feeling,  akin  in  nature  to 
what  we  call  a  nervous  shock.  In  one  case  we  found  con- 
clusive proof  that  when  a  rapid  succession  of  such  waves 
yield  a  rapid  succession  of  such  units  of  feeling,  there 
results  the  continuous  feeling  known  as  a  sensation;  and 
that  the  quality  of  the  feeling  changes  when  these  waves 
and  corresponding  units  of  feeling  recur  with  a  different 
rapidity.  Further,  it  was  shown  that  by  unions  among 
simultaneous  series  of  such  units  recurring  at  unlike 
rates,  countless  other  seemingly-simple  sensations  are  pro- 
duced. And  we  inferred  that  what  unquestionably  holds 
among  these  primary  feelings  of  one  order,  probably  holds 
among  primary  feelings  of  all  orders.  To  what  does  this 
conclusion  amount,  expressed  in  another  way?  It  amounts 
to  the  conclusion  that  one  of  these  feelings  which,  as 
introspectively  contemplated,  appears  uniform,  is  really 
generated  by  the  perpetual  assimilation  of  a  new  pulse  of 
feeling  to  pulses  of  feeling  immediately  preceding  it;  the 
sensation  is  constituted  by  the  linking  of  each  vivid  pulse 
as  it  occurs,  with  the  series  of  past  pulses  that  were  severally 
vivid  but  have  severally  become  faint.  And  what,  otherwise 
stated,  is  the  conclusion  that  compound  sensations  result 
from  unions  among  different  concurrent  series  of  such 
pulses?  It  is  that  while  the  component  pulses  of  each 
series  are,  as  they  occur,  severally  assimilated  to,  or  linked 
"with,  preceding  pulses  of  their  own  kind,  they  are  also 


THE  COMPOSITION  OF  MIND.  185 

severally  combined  in  some  relation  with  the  pulses  of  con- 
current series;  and  the  compound  sensation  so  generated 
is  known  as  different  from  other  compound  sensations  of 
the  same  order,  by  virtue  of  some  speciality  in  the  relations 
among  the  concurrent  series. 

Consider  now,  under  its  most  general  form,  the  process  of 
composition  of  Mind  described  in  foregoing  sections.  It 
is  no  other  than  this  same  process  carried  out  on  higher  and 
higher  platforms,  with  increasing  extent  and  complication. 
As  we  have  lately  seen,  the  feelings  called  sensations  cannot 
of  themselves  constitute  Mind,  even  when  great  numbers  of 
various  kinds  are  present  together.  Mind  is  constituted 
only  when  each  sensation  is  assimilated  to  the  faint  forms 
of  antecedent  like  sensations.  The  consolidation  of  suc- 
cessive units  of  feeling  to  form  a  sensation,  is  paralleled 
in  a  larger  way  by  the  consolidation  of  successive  sensations 
to  form  what  we  call  a  knowledge  of  the  sensation  as  such 
or  such — to  form  the  smallest  separable  portion  of  what  we 
call  thought,  as  distinguished  from  mere  confused  sentiency. 
So  too  is  it  with  the  rela,tions  among  those  feelings  that 
occur  together  and  limit  one  another  in  space  or  time. 
Each  of  these  relations,  so  long  as  it  stands  alone  in  ex- 
perience with  no  antecedent  like  relations,  is  not  fully 
cognizable  as  a  relation:  it  assumes  its  character  as  a 
component  of  intelligence  only  when,  by  recurrence  of 
it,  there  is  produced  a  serial  aggregate  of  such  rela- 
tions. Observe  further  that  while  each  special 
sensation  is  raised  into  a  proximate  constituent  of  simple 
thought  only  by  being  fused  with  like  predecessors,  it 
becomes  a  proximate  constituent  of  compound  thought 
by  simultaneously  entering  into  relations  of  unlikeness 
with  other  sensations  which  limit  it  in  space  or  time; 
just  as  we  saw  that  the  units  or  pulses  that  form  simple 
sensations  by  serial  union  with  their  kind,  may  simul- 
taneously help  to  form  complex  sensations  by  entering 
into  relations  of  difference  with  units  of  other   kinds. 


186  THE  INDUCTIONS  OP  PSYCHOLOGY. 

The  same  thing  obviously  holds  of  the  relations  them- 
selves, that  exist  between  these  unlike  sensations.  And 
thus  it  becomes  manifest  that  the  method  by  which  simple 
sensations,  and  the  relations  among  them,  are  compounded 
into  states  of  definite  consciousness,  is  essentially  analogous 
to  the  method  by  which  primitive  units  of  feeling  are  com- 
pounded into  sensations. 

The  next  higher  stage  of  mental  composition  shows  us 
'this  process  repeating  itself.  The  vivid  cluster  of  related 
sensations  produced  in  us  by  a  special  object,  has  to  be 
united  with  the  faint  forms  of  clusters  like  it  that  have  been 
before  produced  by  such  objects.  What  we  call  knowing 
the  object,  is  the  assimilation  of  this  combined  group  of 
real  feelings  it  excites,  with  one  or  more  preceding  ideal 
groups  which  objects  of  the  same  kind  once  excited;  and 
the  knowledge  is  clear  only  when  the  series  of  ideal 
groups  is  long.  Equally  does  this  principle  hold 

of  the  connexions,  static  and  dynamic,  between  each  such 
special  cluster  and  the  special  clusters  generated  by  other 
objects.  Knowledge  of  the  powers  and  habits  of  things, 
dead  and  living,  is  constituted  by  assimilating  the  more  or 
less  complex  relations  exhibited  by  their  actions  in  space 
and  time  with  other  such  complex  relations.  If  we  cannot 
so  assimilate  them,  or  parts  of  them,  we  have  no  knowledge 
of  their  actions. 

That  the  same  law  of  composition  continues  without  de- 
finite limit  through  tracts  of  higher  consciousness,  formed 
of  clusters  of  clusters  of  feelings  held  together  by  relations 
of  an  extremely  involved  kind,  scarcely  needs  adding. 

§  75.  How  clearly  the  evolution  of  Mind,  as  thus  traced 
through  ascending  stages  of  composition,  conforms  to  the 
laws  of  Evolution  in  general,  will  be  seen  as  soon  as  it  is 
said.  We  will  glance  at  the  correspondence  under  each  of 
its  leading  aspects. 

Evolution  is  primarily  a  progressing  integration;  and 


THE  COMPOSITION  OF  MIND.  187 

througliout  this  chapter,  as  well  as  the  last,  progressing  in- 
tegration has  thrust  itself  upon  us  as  the  fundamental  fact 
in  mental  evolution.  We  came  upon  it  quite  unexpectedly 
in  the  conclusion  that  a  sensation  is  an  integrated  series  of 
nervous  shocks  or  units  of  feeling;  and  in  the  further  con- 
clusion that  by  integration  of  two  or  more  such  series,  com- 
pound sensations  are  formed.  We  have  lately  seen  that  by 
an  integration  of  successive  like  sensations,  there  arises  the 
knowledge  of  a  sensation  as  such  or  such;  and  that  each 
sensation  as  it  occurs,  while  thus  integrated  with  its  like, 
also  unites  into  an  aggregate  with  other  sensations  that 
limit  it  in  space  or  time.  And  we  have  similarly  seen  that 
the  integrated  clusters  resulting,  enter  into  higher  in- 
tegrations of  both  these  kinds;  and  so  on  to  the 
end.  The  significance  of  these  facts  will  be  ap- 

preciated when  it  is  remembered  that  the  tracts  of  con- 
sciousness in  which  integration  is  undecided,  are  tracts  of 
consciousness  hardly  included  in  what  we  commonly  think 
of  as  Mind;  and  that  the  tracts  of  consciousness  presenting 
the  attributes  of  Mind  in  the  highest  degree,  are  those  in 
which  the  integration  is  carried  furthest.  Hunger,  thirst, 
nausea,  and  visceral  feelings  in  general,  as  well  as  feelings 
of  love,  hatred,  anger,  &c.,  which  cohere  little  with  one 
another  and  with  other  feelings,  and  thus  integrate  but 
feebly  into  groups,  are  portions  of  consciousness  that  play 
but  subordinate  parts  in  the  actions  we  chiefly  class  as 
mental.  Mental  actions,  ordinarily  so  called,  are  nearly  all 
carried  on  in  terms  of  those  tactual,  auditory,  and  visual  feel- 
ings, which  exhibit  cohesion,  and  consequent  ability  to  inte- 
grate, in  so  conspicuous  a  manner.  Our  intellectual  opera- 
tions are  indeed  mostly  confined  to  the  auditory  feelings  (as 
integrated  into  words)  and  the  visual  feelings  (as  integrated 
into  impressions  and  ideas  of  objects,  their  relations,  and 
their  motions).  After  closing  the  eyes  and  observing  how 
relatively-immense  is  the  part  of  intellectual  consciousness 
that  is  suddenly  shorn  away,  it  will  be  manifest  that  the 


188  THE  INDUCTIONS  OP  PSYCHOLOGY. 

most  developed  portion  of  perceptive  Mind  is  formed  of 
these  visual  feelings  which  cohere  so  rigidly,  which  inte- 
grate into  such  large  and  numerous  aggregates,  and  which 
re-integrate  into  aggregates  immensely  exceeding  in  their 
degree  of  composition  all  aggregates  formed  by  other  feel- 
ings. And  then,  on  rising  to  what  we  for  convenience  dis- 
tinguish as  rational  Mind,  we  find  the  integration  taking  a 
still  wider  reach. 

The  ascending  phases  of  Mind  show  us  no  less  conspicu- 
ously, the  increasing  heterogeneity  of  these  integrated 
aggregates  of  feelings.  In  the  last  chapter,  we  saw  how 
sensations  that  are  all  composed  of  units  of  one  kind,  are 
rendered  heterogeneous  by  the  combination  and  re-combina- 
tion of  such  units  in  multitudinous  ways.  We  have  lately 
seen  that  the  portions  of  consciousness  occupied  by  the  in- 
ternal bodily  feelings  and  by  the  emotions,  are,  as  judged 
by  introspection,  relatively  very  simple  or  homogeneous: 
thirst  is  not  made  up  of  contrasted  parts,  nor  can  we 
separate  a  gust  of  passion  into  many  distinguishable  com- 
ponents. But  on  passing  upwards  to  intellectual  conscious- 
ness, there  meets  us  an  increasing  variety  of  kinds  of  feel- 
ings present  together.  When  we  come  to  the  auditory  feel- 
ings, which  play  so  important  a  part  in  processes  of  thought, 
we  find  that  the  groups  of  them  are  formed  of  many  com- 
ponents, and  that  those  groups  of  groups  used  as  symbols  of 
propositions  are  very  heterogeneous.  As  before  however 
with  integration,  so  here  with  heterogeneity,  a  far  higher 
degree  is  reached  in  that  consciousness  formed  of  visual  feel- 
ings, which  is  the  most  developed  part  of  perceptive  Mind. 
And  much  more  heterogeneous  still  are  those  tracts  of  con- 
sciousness distinguished  as  ratiocinative  tracts,  in  which  the 
multiform  feelings  given  us  by  objects  through  eyes,  ears, 
and  tactual  organs,  nose,  and  palate,  are  formed  into  con- 
ceptions that  answer  to  the  objects  in  all  their  attributes,  and 
all  their  activities. 

With  equal  clearness  does  Mind  display  the  further  trait 


THE  COMPOSITION  OF  MIND.  189 

of  Evolution — increase  of  definiteness.  Both  the  centrally- 
initiated  feelings  and  the  internal  peripherally-initiated  feel- 
ings, which  play  so  secondary  a  part  in  what  we  understand 
as  Mind,  we  found  to  be  very  vague — very  imperfectly 
limited  by  one  another.  Contrariwise,  it  was  shown  that 
the  mutual  limitations  are  decided  among  those  peripherally- 
initiated  feelings  which,  arising  on  the  outer  surface,  enter 
largely  into  our  intellectual  operations;  and  that  the  visual 
feelings,  which  enter  by  far  the  most  largely  into  our  in- 
tellectual operations,  are  not  only  by  far  the  sharpest  in 
their  mutual  limitations,  but  form  aggregates  that  are 
much  more  definitely  circumscribed  than  any  others,  and 
aggregates  between  which  there  exist  relations  much  more 
definite  than  those  entered  into  by  other  aggregates. 

Thus  the  conformity  is  complete.  Mind  rises  to  what  are 
universally  recognized  as  its  higher  developments,  in  pro- 
portion as  it  manifests  the  traits  characterizing  Evolution  in 
general  {First  Prvndples^  §§  98 — 145).  A  confused  sen- 
tiency,  formed  of  recurrent  pulses  of  feeling  having  but 
little  variety  of  kind  and  but  little  combination,  we  may 
conceive  as  the  nascent  Mind  possessed  by  those  low  types 
in  which  nerves  and  nerve-centres  are  not  yet  clearly  dif- 
ferentiated from  one  another,  or  from  the  tissues  in  which 
they  lie.  At  a  stage  above  this,  while  yet  the  organs  of  the 
higher  senses  are  rudimentary,  and  such  nerves  as  exist  are 
incompletely  insulated,  Mind  is  present  probably  under  the 
form  of  a  few  sensations,  which,  like  those  yielded  by  our 
own  viscera,  are  simple,  vague,  and  incoherent.  And  from 
this  upwards,  the  mental  evolution  exhibits  a  differentia- 
tion of  these  simple  feelings  into  the  more  numerous  kinds 
which  the  special  senses  yield;  an  ever-increasing  integra- 
tion of  such  more  varied  feelings  with  one  another  and  with 
feelings  of  other  kinds;  an  ever-increasing  multiformity  in 
the  aggregates  of  feelings  produced ;  and  an  ever-increasing 
distinctness  of  structure  in  such  aggregates.  That  is  to  say, 
there  goes  on  subjectively  a  change  "  from  an  indefinite,  in- 
coherent homogeneity  to  a  definite,  coherent  heterogene- 


190  THE  INDUCTIONS  OF  PSYCHOLOGY. 

ity;  "  parallel  to  that  redistribution  of  matter  and  motion 
which  constitutes  Evolution  as  objectively  displayed. 

§  76.  The  correspondences  between  these  views  of  mental 
composition  and  the  general  truths  respecting  nervous 
structure  and  nervous  functions  set  forth  in  the  last  part, 
must  be  briefly  indicated. 

Speaking  generally,  feelings  and  the  relations  between 
feelings,  correspond  to  nerve-corpuscles  and  the  fibres  which 
connect  nerve-corpuscles;  or  rather, to  the  molecular  changes 
of  which  nerve-corpuscles  are  the  seats,  and  the  molecular 
changes  transmitted  through  fibres.  The  psychical  relation 
between  two  feelings,  answers  to  the  physical  relation  be- 
tween two  disturbed  portions  of  grey  matter,  which  are 
put  in  such  direct  or  indirect  communication  that  some  dis- 
charge takes  place  between  them. 

The  fact  that,  as  elements  of  consciousness,  the  relations 
between  feelings  are  very  short  in  comparison  with  the  feel- 
ings they  unite,  has  thus  its  physiological  equivalent  in  the 
fact  that  the  transmission  of  a  wave  of  change  through  a 
nerve-fibre,  is  very  rapid  in  comparison  with  the  transforma- 
tion it  sets  up  in  a  nerve-centre.  If  we  consider  each  such 
transformation  to  be  physically  that  which  psychically  we 
consider  a  unit  of  feeling,  then,  remembering  its  appreciable 
duration,  we  may  understand  how  It  happens  that  when  the 
waves  of  molecular  change  brought  by  an  in-coming  nerve- 
fibre  exceed  a  certain  rate  of  recurrence,  the  transformation 
set  up  each  lasts  till  the  next  commences;  and  hence  the 
corresponding  units  of  feeling  become  fused  into  a  con- 
tinuous feeling  or  sensation. 

We  have  seen  that  predominance  of  the  relational  element 
of  Mind,  characterizes  the  peripherally-initiated  tracts  of 
consciousness  which  external  objects  produce.  Between  this 
fact  and  the  facts  of  nervous  structure,  there  is  an  obvious 
agreement.  Take  the  case  of  the  eye.  The  retina  being  an 
area  formed  of  an  immense  number  of  sensitive  elements, 
close  to,  but  separate  from,  one  another,  and  having  each 


THE  COMPOSITION  OF  MIND.  191 

an  independent  centripetal  fibre;  it  results  that  the  rela- 
tions that  may  be  established  between  each  one  and  all  the 
others  are  enormous  in  number,  and  that  enormous  numbers 
of  relations  may  be  established  between  simultaneously- 
excited  clusters  of  them  and  other  simultaneously-excited 
clusters.  The  sharpness  of  mutual  limitation  of  the  feelings 
and  clusters  of  feelings  here  initiated,  is  also  clearly  due  to 
these  same  structural  peculiarities;  as  are  also  their  rigid 
cohesions  and  extensive  integrations.  Without  naming  the 
intermediate  cases,  it  will  suffice  if  we  pass  to  the  other 
extreme  and  observe  how,  in  the  visceral  nervous  system, 
whence  come  feelings  that  are  so  simple,  so  indefinite,  and 
so  incoherent,  there  is  an  absence  of  the  appliances 
which  secure  independent  excitements  of  adjacent  nerve- 
terminations. 

A  further  harmony  of  the  same  order  may  be  noted.  The 
relational  element  of  Mind,  as  shown  in  mutual  limitation,  in 
strength  of  cohesion,  and  in  degree  of  clustering,  is  greater 
between  feelings  of  the  same  order  than  between  feelings  of 
one  order  and  those  of  another.  This  answers  to  the  fact 
that  the  bundles  of  nerve-fibres  and  clusters  of  nerve- 
vesicles  belonging  to  feelings  of  one  order,  are  combined 
together  more  directly  and  intimately  than  they  are  with  the 
fibres  and  vesicles  belonging  to  feelings  of  other  orders. 
Similarly,  it  holds  among  feelings  of  different  orders,  that 
the  readiness  to  enter  into  relations  is  much  greater  between 
those  arising  in  the  higher  sense-organs,  which  have  nervous 
centres  closely  connected,  than  between  them  and  the  vis- 
ceral feelings  which  arise  in  parts  of  the  nervous  system 
that  communicate  but  indirectly  with  the  higher  centres. 
Even  an  anomaly  appears  thus  explicable.  That  such 
unrelational  feelings  as  smells  have  exceptional  powers  of 
calling  up  remembrances  of  past  scenes,  is  probably  due  to 
the  fact  that  the  olfactory  centres  are  outgrowths  from  the 
cerebral  hemispheres. 

"We  have  seen  that  the  development  of  Mind  is  funda- 
mentally an  increasing  integration  of  feelings  on  successively- 


192  THE  INDUCTIONS  OP  PSYCHOLOGY. 

higher  stages,  along  with  which  there  go  increasing  hetero- 
geneity and  definiteness;  and  these  traits  answer  to  traits  in 
the  evolution  of  the  nervous  system  before  contemplated. 
For  we  found  that  along  with  growing  distinctness  and 
multiformity  of  structure,  there  is  throughout  an  advancing 
integration  of  structure  as  well  as  of  mass.    (See  §  8.) 

One  more  correspondence  of  moment  may  be  pointed  out 
— a  correspondence  that  replaces  a  supposed  discordance. 
The  most  developed  and  conspicuous  part  of  Mind  chiefly 
occupies  men's  attention;  and  hence  they  speak  of  Mind 
and  Intelligence  as  equivalents.  As  hinted  in  §  7,  even 
physiologists,  intending  to  ignore  all  pre-conceptions,  have 
been  led  into  difficulties  of  interpretation  by  inadvertently 
setting  out  with  this  belief  as  their  postulate.  But  Mind  is 
not  wholly,  or  even  mainly.  Intelligence.  We  have  seen  that 
it  consists  largely,  and  in  one  sense  entirely,  of  Feelings. 
Not  only  do  Feelings  constitute  the  inferior  tracts  of  con- 
sciousness, but  Feelings  are  in  all  cases  the  materials  out  of 
which,  in  the  superior  tracts  of  consciousness.  Intellect  is 
evolved  by  structural  combination.  Everywhere  Feeling  is 
the  substance  of  which,  where  it  is  present.  Intellect  is 
the  form.  And  where  Intellect  is  not  present,  or  but  little 
present,  Mind  consists  of  feelings  that  are  unformed  or  but 
little  formed.  Intellect  comprehends  only  the  relational 
elements  of  Mind;  and  to  omit  Feelings  is  to  omit  the 
terms  between  which  the  relations  exist.  The  recognition  of 
this  truth  saves  us  from  the  error  of  looking  for  a  regular 
correspondence  between  the  development  of  the  nervous 
system  and  the  degree  of  Intelligence.  As  in  §  7  we  saw  that 
the  size  of  the  nervous  system  varies  partly  as  the  quantity 
of  motion  evolved,  and  partly  as  the  complexity  of  that 
motion;  so  here  we  see  that  the  size  of  the  nervous  system 
varies  partly  as  the  quantity  of  Feeling  (which  has  a  general 
relation  to  the  quantity  of  motion)  and  partly  as  the  degree 
of  Intellect  (which  has  a  general  relation  to  the  complexity 
of  the  motion).  And  thus  interpreting  the  facts,  supposed 
anomalies  disappear. 


CHAPTEK  m. 

THE    EELATTVITY    OF    FEELEiTGS. 

§  Y7.  Mind  being  composed  of  Feelings  and  the  Kela- 
tions  between  Feelings,  and  the  aptitudes  of  Feelings  for 
entering  into  Eolations  varying  with  their  kinds,  the  Relati- 
vity of  Feelings  is  an  expression  applicable,  in  one  sense,  to 
certain  of  the  purely  subjective  phenomena  described  in  the 
last  chapter.  But  it  is  here  to  be  understood  in  quite  a  dif- 
ferent sense.  Having  contemplated  Feelings  in  their  rela- 
tions to  one  another  as  components  of  consciousness,  we 
have  now  to  contemplate  them  in  their  relations  to  the 
things  beyond  consciousness  by  which  they  are  produced. 

Moreover,  the  things  beyond  consciousness  here  to  be 

considered,  are  not  the  nerve-disturbances  which  are  the 

physical  sides  of  what  we  call  feelings  on  their  psychical 

sides:  already,  in  the  chapter  on  ^stho-Physiology,  the 

relations  between  the  subjective  and  objective  faces  of 

nervous  changes  have  been  described.    Our  present  inquiry 

is  into  the  nature  of  the  connexions  between  feelings,  and 

forces  existing  outside  the  organism.     To  treat  of  these 

without  going  over  any  ground  before  traversed  is  difficult; 

since  an  external  action  being  related  to  a  feeling  only 

through  an  intermediate  nervous  change,  the  intermediation 

cannot  well  be  left  out  of  sight.    Occasional  brief  repetitions 

must  therefore  be  excused. 

It  should  be  further  premised  that  we  are  here  concerned 

193 


194  THE  INDUCTIONS  OF  PSYCHOLOGY. 

mainly  with  peripherally-initiated  feelings  which  have  exter- 
nal origins;  or  rather,  with  those  primary  or  vivid  forms  of 
them  which  we  call  real,  in  contradistinction  to  the  second- 
ary or  faint  forms  we  call  ideal. 

§  78.  The  general  truth,  familiar  to  all  students  of  Psy- 
chology, which  it  is  the  object  of  this  chapter  to  present 
under  its  many  aspects,  is  that  though  internal  feeling 
habitually  depends  on  external  agent,  yet  there  is  no  likeness 
between  them  either  in  kind  or  degree.  The  connexion 
between  objective  cause  and  subjective  effect  is  conditioned 
in  ways  extremely  complex  and  variable — ways  which  we 
will  proceed  to  consider  seriatim. 

We  shall  find  that  each  set  of  conditions  so  modifies  the 
connexion  between  objective  cause  and  subjective  effect  as 
to  determine  the  qualitative  character  of  the  effect.  In 
other  words,  the  same  agent  produces  feelings  of  quite 
unlike  natures  according  to  the  circumstances  under  which 
it  acts. 

We  shall  further  see  that,  besides  this  qualitative  unlike- 
ness,  there  is  a  quantitative  unlikeness.  Between  the  outer 
force  and  the  inner  feeling  it  excites,  there  is  no  such  cor- 
relation as  that  which  the  physicist  calls  equivalence — nay, 
the  two  do  not  even  maintain  an  unvarying  proportion. 
Equal  amounts  of  the  same  force  arouse  different  amounts 
of  the  same  feeling,  if  the  circumstances  differ.  Only  while 
all  the  conditions  remain  constant  is  there  something  like  a 
constant  ratio  between  the  physical  antecedent  and  the 
psychical  consequent. 

§  79.  Were  I  not  bound  to  enumerate  all  aspects  of  this 
relativity,  it  would  be  needless  to  say  that  the  connexion 
between  the  outer  agent  and  the  inner  feeling  generated  by 
it,  depends  on  the  structure  of  the  species. 

Obviously  the  forms  of  sensation  that  can  be  roused  in 
the  consciousness  of  a  creature,  are  primarily  determined  by 


THE  RELATIVITY  OP  FEELINGS.  196 

the  peripheral  organs  with  which  its  type  is  endowed.  This 
is  so  even  with  the  most  general  of  the  sensations — that  of 
Touch.  A  Crustacean,  everywhere  enclosed  in  a  hard  exo- 
skeleton,  can  have  no  such  tactual  impressions  as  those  which 
are  possible  to  a  soft-skinned  animal.  The  impressions 
received  from  the  ends  of  its  limbs  and  claws  when  they 
come  in  contact  with  external  objects,  may  be  compared  to 
those  which  a  man  receives  from  poking  objects  with  the 
end  of  his  walking-stick.  Still  more  manifestly 

are  the  special  sensations  dependent  for  their  qualities  on 
the  presence  of  special  sense-organs.  Take  the  auditory 
sensations.  Various  aquatic  creatures  that  have  no  developed 
organs  of  Hearing,  are  nevertheless  affected  by  those  vibra- 
tions which  to  creatures  better  endowed  are  sonorous. 
When  such  vibrations  are  propagated  through  their  medium, 
they  contract  themselves,  or  they  withdraw  into  their  shells 
if  they  have  them.  We  may  reasonably  assume  that  what 
they  feel  is  a  jar  somewhat  resembling  the  jar  received  by 
the  hand  from  a  vibrating  musical  instrument.  But  in  any 
ease,  the  quality  of  the  feeling  excited  in  these  lower  animals 
by  sonorous  waves,  is  wholly  unlike  the  quality  of  the  feel- 
ing which  such  waves  excite  in  higher  animals. 

That,  qualities  being  alike,  the  quantities  of  the  feelings 
produced  by  given  agents  vary  with  the  specific  structures, 
is  an  equally  familiar  truth.  In  a  bird  or  mammal  having 
eyes  that  fit  it  for  nocturnal  habits,  the  sensation  aroused  by 
a  faint  light,  is  much  greater  than  is  aroused  by  it  in  a  di- 
urnal bird  or  mammal;  and  the  light  which  gives  to  a  di- 
urnal creature  a  moderate  amount  of  sensation  suffices  to 
dazzle  the  nocturnal  creature  by  its  excess.  Simi- 

larly with  the  olfactory  feelings.  An  odour  which  has  no 
appreciable  effect  on  the  consciousness  of  a  man,  has  a  very 
marked  effect  on  the  consciousness  of  a  dog.  Even  varie- 
ties of  dogs,  as  the  greyhound  and  the  beagle,  yield  us 
evidence  of  decided  quantitative  differences  between  the 

mental  changes  caused  by  the  same  odour. 
U 


196  THE  INDUCTIONS  OF  PSYCHOLOGY. 

These  few  instances  warrant  us  in  suspecting  that  in  no 
two  species  does  a  given  amount  of  a  given  outer  agent 
excite  exactly  the  same  kind  and  quantity  of  feeling. 

§  80.  This  apparently  hasty  generalization  is  justified  by 
the  generalization  to  which  we  come  next;  namely,  that 
within  the  same  species  the  relation  between  objective  cause 
and  subjective  effect  varies  both  qualitatively  and  quantita- 
tively with  the  constitution — varies,  that  is,  with  the  in- 
dividual structure. 

That  peculiarity  of  vision  discovered  in  himself  by  Dal- 
ton,  and  sometimes  named  after  him,  yields  an  instance  of 
qualitative  difference.  To  those  organized  as  he  was,  the 
visible  world  does  not  present  all  the  various  feelings  of 
colour  that  it  does  to  mankind  in  general.  Sensations  which 
to  others  seem  strongly  contrasted,  as  red  and  green,  seem 
to  them  the  same.  Whence  we  must  conclude  that  certain 
etherial  undulations  produce  in  such  persons  feelings  unlike 
those    they    produce    in    other    persons.  From 

sentient  states  excited  through  the  ears,  may  be  drawn 
another  illustration.  Aerial  pulses  recurring  at  the  rate  of 
sixteen  per  second  are  perceived  by  some  as  separate 
pulses;  but  by  some  they  are  perceived  as  a  tone  of  very 
low  pitch.  Similarly  at  the  other  extreme.  Vibrations 
exceeding  thirty  thousand  per  second,  are  inaudible  through 
certain  ears;  while  through  ears  that  are,  as  we  may  suppose, 
of  somewhat  unlike  structures,  these  rapid  vibrations  are 
known  as  an  excessively  acute  sound. 

Quantitative  differences  of  sensation  that  are  caused  by 
differences  of  individual  organization,  every  one  observes. 
All  orders  of  sensations  exemplify  them.  Here  are  instances 
from  each.  Thick-skinned  persons  are  insensible  to 

tactual  impressions  which  thin-skinned  persons  clearly  feel; 
and  there  are  persons  by  whom  minute  unlikenesses  of  sur- 
face are  so  distinctly  perceived  that  they  are  employed  to 
judge   of   commodities,   such   as   raw   silk,   by   handling 


THE  RELATIVITY  OF  FEELINGS.  l97 

them.  How  amounts  of  flavour  quite  inappreciable 

by  some  are  readily  appreciable  by  others,  the  dinner-table 
constantly  reminds  us.  And  that  there  are  professional 
tasters,  shows  that  the  gustatory  feeling  produced  by  a  given 
quantity  of  sapid  substance,  is,  in  exceptional  organizations, 
much  greater  than  usual.  With  smells  it  is  the 

same.  There  are  those  to  whom  quite  delicate  perfumes 
seem  of  overpowering  strength.  And  there  are  those  to 
whom  odours  usually  felt  to  be  disgusting  in  the  extreme, 
are  scarcely  perceptible.  Constitutional  differences 

in  quickness  of  hearing,  sometimes  marked  between  persons 
of  the  same  race,  are  more  marked  between  persons  of 
different  races.  By  putting  his  ear  to  the  ground  a  savage 
hears  sounds  inaudible  by  a  civilized  man.  The 

like  holds  with  visual  sensitiveness.  The  Bushman  is  im- 
pressible by  changes  in  the  field  of  view  which  do  not  im- 
press the  European.  And  such  tests  as  occur  in  the  telescopic 
search  for  minute  stars,  show  that,  in  the  same  race,  the 
amount  of  light  which  excites  a  distinct  feeling  in  one 
person,  excites  no  feeling  in  another. 

Thus  we  may  make  wider  the  startling  inference  drawn 
in  the  last  section.  Besides  concluding  that  in  no  two 
species  are  the  subjective  effects  produced  by  given  objec- 
tive actions  absolutely  alike,  qualitatively  and  quantita- 
tively; we  may  conclude  that  they  are  absolutely  alike  in  no 
two  individuals  of  the  same  species. 

§  81.  Whatever  there  may  seem  of  excess  in  this  state- 
ment will  disappear  when  we  remember  that  even  in  the 
same  individual  the  quantity,  if  not  the  quality,  of  the  feel- 
ing excited  by  an  external  agent  constant  in  kind  and  de- 
gree, varies  according  to  the  constitutional  state. 

Of  qualitative  variations  we  have  but  vague  and  indirect 
evidence.  Still  the  experiences  of  invalids  yield  reason  to 
suspect  that  they  occur.  There  are  abnormal  states  of  the 
nervous  system  during  which  illusive  sensations  trouble  the 


198  THE  INDUCTIONS  OF  PSYCHOLOGY. 

patient.  The  consciousness  of  a  disagreeable  smell  which  is 
one  of  the  premonitory  symptoms  of  an  epileptic  fit,  may  be 
named  as  an  instance.  And  if  feelings  of  purely  subjective 
origin,  so  strong  as  to  be  mistaken  for  feelings  of  objective 
origin,  may  arise  from  extreme  nervous  derangements,  it  is 
reasonably  inferable  that  smaller  nervous  derangements 
will  often  arouse  vague  subjective  states  which  may  mingle 
with,  and  qualify,  the  feelings  objectively  originated. 

The  quantitative  variations  which  variations  of  constitu- 
tional state  entail  among  the  feelings  produced  by  equal 
external  agents,  are  very  familiar.  As  before,  some  are  con- 
sequent on  derangements  of  health  and  some  on  advancing 
years.  In  certain  conditions  of  nervous  irritabi- 

lity, sounds  of  ordinary  strength  seem  intolerably  loud; 
daylight  becomes  unbearable  from  the  excess  of  visual  feel- 
ing it  causes;  and  even  the  skin  becomes  unduly  sensitive: 
there  is  what  is  called  hyper-eesthesia.  Contrariwise,  there 
are  deviations  from  health  characterized  by  an  anaesthesia 
allied  to  that  artificially  caused — a  state  of  comparative 
indifference  to  amounts  of  external  stimuli  which  commonly 
arouse  much  feeling.  How  along  with  decline  of 

vigour  in  old  age  there  goes  an  increasing  anaesthesia  of 
one  or  more  kinds,  we  have  daily  proof.  There  is  dimness 
of  sight;  there  is  dulness  of  hearing;  there  is  often  obtuse- 
ness  of  taste. 

Thus,  besides  seeing  that  the  subjective  effect  produced 
by  each  objective  cause  varies  with  the  structure  of  the 
species,  and  varies  with  the  structure  of  the  individual  of 
the  species,  we  see  that  it  varies  with  the  constitutional 
state  of  the  individual — often  in  a  marked  degree.  Very 
possibly  the  ratio  is  never  twice  the  same ;  but  always  differs 
infinitesimally,  if  not  appreciably. 

§  82.  The  kind  and  degree  of  effect  which  an  external 
physical  stimulus  produces  on  the  psychical  state,  depends 
also  on  the  part  of  the  organism  subject  to  it.    Equal  quan- 


THE  RELATIVITY  OP  FEELINGS.  I99 

titles  of  the  same  force  excite  feelings  widely  unlike,  quali- 
tatively and  quantitatively,  according  to  tlie  structures  of 
the  peripheral  organs  on  which  they  fall. 

The  qualitative  differences  we  recognize  so  much  as 
matters  of  course  that  we  forget  their  significance.  Here, 
however,  they  must  not  be  passed  over.  Many 

kinds  of  matter  which,  when  applied  to  the  skin  at  large, 
cause  only  sensations  of  touch,  cause,  when  applied  to  the 
tongue,  sensations  of  touch  and  taste;  or,  if  they  are  kinds 
of  matter  having  the  tastes  we  call  pungent,  they  arouse  in 
the  skin  sensations  of  heat  or  tingling.  Similarly 

with  volatile  substances.  A  whiff  of  ammonia  coming  in 
contact  with  the  eyes,  produces  a  smart;  getting  into  the 
nostrils,  excites  the  consciousness  we  describe  as  an  intolera- 
bly strong  odour;  being  condensed  on  the  tongue,  generates 
an  acrid  taste ;  while  ammonia  applied  in  solution  to  a  tender 
part  of  the  skin,  makes  it  burn,  as  we  say.  The 

feeling  caused  by  sonorous  undulations,  already  adverted  to 
as  varying  with  the  structure  of  the  species,  must  be  named 
here  also  as  varying  with  the  structure  of  the  part  affected. 
A  vibrating  tuning-fork  touched  with  the  fingers,  gives 
them  a  sense  of  jar;  held  between  the  teeth,  it  gives  this 
same  sense  to  the  parts  in  which  they  are  imbedded,  while 
by  communication  through  the  bones  of  the  skull,  its  vibra- 
tions so  affect  the  auditory  apparatus  as  to  awaken  a  con- 
sciousness of  sound — a  consciousness  which  alone  results  if 
the  tuning-fork  does  not  touch  the  body.  The 

different  sensations  excited  by  etherial  undulations  on  the 
unmodified  integument  and  on  those  modified  portions  of  it 
which  constitute  eyes  {Principles  of  Biology,  §  295)  yield 
further  illustrations.  The  Sun's  rays  falling  on  the  hand 
cause  a  sensation  of  heat  but  no  sensation  of  light;  and 
falling  on  the  retina  cause  a  sensation  of  light  but  no  sensa- 
tion of  heat.  As  Professor  Tyndall  has  proved  by  experi- 
ment on  himself,  the  retina  is  insensible  to  heat-rays  of 
considerable  concentration. 


200  THE  INDUCTIONS  OF  PSYCHOLOGY. 

That  the  relation  between  an  outer  force  and  the  inner 
feeling  it  arouses,  varies  quantitatively  according  to  the  part 
of  the  body  acted  upon,  there  are  many  proofs,  of  which  one 
or  two  will  suffice.  The  arched  under-surface  of 

the  foot  experiences  an  intense  sensation  of  tickling  from  a 
gentle  touch  which  generates  a  much  feebler  sensation  of 
this  kind  elsewhere.  Conversely,  the  thick  skin  of  the  heel 
bears  with  comparatively  little  pain  the  long-continued 
pressure  of  a  hard  prominence  which  would  be  intolerable 
to  the  back  of  the  hand.  The  feelings  caused  by 

exposing  different  parts  of  the  skin  to  the  same  heat,  are  not 
in  most  cases  conspicuously  unlike  in  degree;  but  there  is 
one  case  in  which  they  are.  When  drinking  a  liquid  the  heat 
of  which  is  quite  bearable  by  that  part  of  the  upper  lip  usu- 
ally immersed,  it  may  be  observed  that  if  the  lip  is  acci- 
dentally dipped  deeper,  so  as  to  immerse  a  little  of  the  outer 
skin,  a  sensation  of  scalding  results. 

We  find,  then,  that  the  same  external  agent  acting  on 
different  peripheral  organs,  generates  states  of  consciousness 
which  have  in  many  cases  no  likenesses  of  kind  whatever, 
and  have  in  other  cases  immense  unlikenesses  of  degree. 

§  83.  The  state  of  the  part  affected,  as  well  as  its  structure, 
has  a  share  in  determining  the  relation  between  outer  agent 
and  inner  feeling.  Already  in  the  chapter  on  iEstho- 
Physiology,  it  has  been  shown  that  the  ratio  borne  by  the 
change  set  up  in  a  nerve-termination  to  the  feeling  elicited, 
varies  with  the  local  conditions.  Obviously  this  involves  a 
concomitant  variation  in  the  ratio  between  the  amount  of 
external  force  which  initiates  the  nervous  change,  and  the 
amount  of  feeling  that  eventually  results.  It  will  suffice  to 
recall  the  several  causes  of  the  variation. 

The  temperature  of  the  part  is  one  of  them.  Between 
the  state  of  local  insensibility  produced  by  excessive  cold, 
and  the  state  of  sensibility  accompanying  natural  warmth, 
there  are  states  showing  all  gradations  in  the  proportion 


THE  RELATIVITY  OP  PEELINGS.  201 

which  the  incident  force  bears  to  the  feeling  called 
forth. 

Local  anaemia  affects  this  proportion  by  diminishing  the 
quantity  of  sensation  which  a  given  amount  of  outer  actior. 
generates;  and  local  hyperaemia,  by  increasing  it — often 
extremely.  Hyperaemia,  however,  in  certain  cases  (pos- 
sibly by  putting  an  obstacle  between  the  outer  agent  and 
the  nerves  to  be  affected)  decreases  the  amount  of  feeling 
generated;  as  in  the  partial  or  complete  loss  of  taste  and 
smell  caused  by  a  bad  cold. 

The  condition  of  the  structures  concerned  as  modified  by 
previous  discharge  of  their  functions,  is  a  further  cause  of 
variation  in  the  ratio  between  the  objective  actions  and  the 
subjective  effects  due  to  them.  Sensory  organs  worn  by 
strong  excitements  recently  undergone,  require  greater  ex- 
ternal forces  to  arouse  the  same  amounts  of  internal  feelings. 
This  is  so  with  touches,  tastes,  smells,  as  well  as  visual  and 
auditory  impressions. 

One  more  cause  of  variation,  occurring  in  a  special  class  of 
cases,  must  be  added.  The  sensation  that  follows  contact 
with  matter  hotter  or  colder  than  the  body,  depends  less  on 
the  temperature  of  the  matter  than  on  the  contrast  between 
its  temperature  and  that  of  the  body.  On  going  into  a  warm 
bath  or  into  cold  water,  the  heat  or  the  cold  seems  greater 
than  it  does  after  a  short  interval,  during  which  the  thermal 
state  of  the  skin  has  approximated  to  that  of  the  water. 
More  striking  still  is  the  evidence  yielded  by  cases  in  which 
the  same  tepid  water  feels  either  warm  or  cold  according  to 
the  temperature  of  the  hand  put  into  it;  nay,  in  which  it 
feels  both  warm  and  cold  to  the  two  hands,  if  one  has  been 
much  heated  and  the  other  much  cooled. 

§  84.  Yet  another  general  fact  remains.  The  relative 
motions  of  subject  and  object,  modify,  both  qualitatively  and 
quantitatively,  the  relations  between  incident  forces  and 
evoked  feelings. 


202  THE  INDUCTIONS  OF  PSYCHOLOGY. 

The  instance  of  qualitative  modification  most  easily  ob- 
served, is  that  produced  in  the  pitch  of  a  sound  by  the 
movement  of  the  sounding  body  towards,  or  away  from,  the 
auditor.  If,  as  an  express  train  passes  through  a  railway- 
station,  the  whistle  happens  to  be  going,  the  tone  heard  by 
each  person  in  the  station,  changes  from  a  higher  to  a  lower 
at  the  moment  the  engine  goes  by  him.  A  still  more 
marked  change  is  perceivable  if  the  auditor,  seated  in  a 
train  travelling  with  considerable  speed  in  one  direction,  is 
passed  by  a  whistling  engine  travelling  rapidly  in  the 
opposite  direction.  Under  such  circumstances  I  have  ob- 
served, at  the  moment  of  passing,  a  fall  in  the  pitch  of  the 
note  amounting  to  a  major  third  or  even  a  fourth.  How 
this  is  due  to  an  alteration  in  the  number  of  aerial  pulses 
reaching  the  ear  in  a  given  time,  need  not  here  be  explained 
at  length.  It  concerns  us  only  to  note  that  the  quality  of 
the  feeling  produced  by  a  sounding  body  is  not  the  same 
when  the  body  is  approaching  or  receding  as  when  sta- 
tionary; and  that  the  quality  of  the  feeling  changes 
with  every  change  in  the  rate  of  approach  or  reces- 
sion. A  remarkable  illustration  of  analogous 
nature,  has  been  disclosed  by  inquiries  respecting  the 
qualities  of  the  lights  radiated  by  different  stars.  Some 
years  since  it  was  suggested  that  possibly  the  apparent 
colours  of  the  stars  are  determined  by  their  motions 
towards,  or  away  from,  the  Earth  at  various  velocities ;  and 
though  this  supposition  has  not  turned  out  to  be  true,  yet  a 
truth  akin  to  it  has  been  discovered.  Though  to  the  naked 
eye,  the  quality  of  the  light  emanating  from  each  star  is  not 
appreciably  affected  by  the  star's  velocity  of  approach  to,  or 
recession  from,  us;  yet,  as  examined  through  the  spectro- 
scope, its  quality  proves  to  be  thus  affected.  Mr.  Huggins 
has  recently  shown  that  the  spectrum  of  Sirius  differs  from 
the  spectrum  he  would  yield  were  he  stationary  relatively  to 
us;  and  differs  in  such  way  as  to  show  that  he  is  moving 
away  from  us  at  a  rate  of  more  than  two  millions  of  miles 


THE  RELATIVITY  OF  FEELINGS.  203 

per  day.  Hence,  in  a  degree  appreciable  under  certain  con- 
ditions, the  nature  of  the  feeling  excited  by  luminiferous 
undulations,  varies  according  to  the  relative  motion  of  the 
observer  and  the  body  emitting  them. 

Of  quantitative  variations  arising  from  relative  motion, 
we  have  a  familiar  instance  in  the  different  feelings  of  heat 
or  of  cold  produced  in  us  by  surrounding  media,  when  we 
are  at  rest  and  when  we  move.  In  a  bath  above  100°,  the 
water  seems  hotter  to  a  limb  that  stirs  than  to  one  that 
is  stationary;  and  every  bather  knows  how  much  colder 
running  water  of  a  given  temperature  feels  than  •  still 
water  of  the  same  temperature — a  contrast  that  becomes 
very  great  when  the  velocity  of  the  water  is  much 
raised,  as  in  a  douche.  Similarly  with  the  air.  A  greater 
chill  is  felt  by  those  who,  instead  of  standing  still,  are  ex- 
posed in  a  carriage  to  ^'  the  wind  of  their  own  speed." 
Though  the  explanation  of  these  differences  is,  that  the 
medium  in  contact  with  the  skin  is  continually  changed 
in  the  one  set  of  cases  and  not  in  the  other,  yet  it  remains 
true  that  the  sensation  varies  in  intensity  as  the  relative 
motion  of  the  medium  varies. 

§  85.  Thus  far  we  have  limited  our  attention  to  the  feel- 
ings excited  by  external  things  acting  on  the  organism.  We 
must  not,  however,  pass  over  the  feelings  which  accompany 
actions  of  the  organism  on  external  things.  Though  here 
the  relation  between  subjective  and  objective  changes  does 
not  obviously  vary  qualitatively,  it  varies  very  much  quan- 
titatively. 

If,  in  muscular  action,  there  took  place  a  transformation 
of  the  feeling  of  muscular  effort  into  an  equivalent  of  me- 
chanical effect ;  then  a  given  amount  of  such  feeling  would 
always  generate  the  same  amount  of  such  effect,  through 
whatever  muscles  expended.  But  the  fact  is  quite  other- 
wise. The  conscious  exercise  of  force  required  when  a 
stone  weight  is  lifted  by  the  little  finger,  far  exceeds  that 


204  THE  INDUCTIONS  OF  PSYCHOLOGY. 

required  when  the  stone  weight  is  grasped  in  the  hand, 
and  lifted  by  the  arm.  Or  again,  the  gymnastic  feat  of 
raising  the  body  up  a  ladder  hand  over  hand,  implies  a 
much  higher  degree  of  the  subjective  state  we  call  exertion 
than  is  implied  by  climbing  up  the  ladder  in  the  usual  way. 
Clearly,  therefore,  a  given  amount  of  feeling  gives  rise 
to  an  amount  of  molar  motion  which  is  large  or  small  ac- 
cording to  the  muscles  used.  This  relation  is  also 
dependent  on  age.  The  sense  of  effort  which  a  child  expe- 
riences in  raising  a  weight,  greatly  exceeds  in  intensity  the 
sense  of  effort  it  will  experience  in  raising  the  same  weight 
by  the  same  muscles  twenty  years  afterwards.  At  maturity, 
a  like  amount  of  sensation  is  the  correlate  of  an  increased 
amount  of  produced  motion.  Similarly,  this  relation 
varies  quantitatively  as  the  constitutional  state  varies. 
After  a  prostrating  illness,  the  feeling  of  strain  that  accom- 
panies the  raising  of  a  limb,  is  as  great  as  that  which  in 
health  accompanies  a  considerable  feat  of  strength. 

§  86.  Were  it  not  that  already  as  much  space  as  can  be 
afforded  has  been  occupied,  it  would  be  well  here  to  illus- 
trate the  ways  in  which  both  the  peripherally-initiated 
feelings  that  arise  in  internal  organs  and  the  centrally- 
initiated  feelings  or  emotions,  have  also  their  several  forms 
of  relativity.  But  it  must  suffice  just  to  indicate  these  ex- 
tensions of  the  general  truth  that  has  been  set  forth. 

For  present  purposes  we  may  fitly  limit  ourselves  to  the 
relativity  of  those  peripherally-initiated  feelings  directly 
traceable  to  environing  agencies.  Their  relativities  we  find 
to  be  of  manifold  kinds.  The  quality  and  the  quantity  of 
the  sensation  produced  by  a  given  amount  of  a  given 
external  force,  vary  not  only  with  the  structure  of  the 
organism,  specific  and  individual,  as  well  as  the  struc- 
ture of  the  part  affected,  but  also  with  the  age,  the  con- 
stitutional state,  the  state  of  the  part  as  modified  by  tem- 
perature, circulation,  and  previous  use,  and  even  with  the 


THE  RELATIVITY  OF  FEELINGS.  206 

relative  motion  of  subject  and  object.  Thus  we  may  count 
up  nine  different  causes  which  affect  qualitatively  or  quanti- 
tatively or  both,  the  relation  between  the  exciting  physical 
agent  and  the  produced  psychical  modification.  These  dif- 
ferent causes  co-operate  in  ever-changing  proportions. 
And  when  we  remember  that  any  change  in  any  one  of  them 
results  in  some  alteration  in  the  kind  or  degree  of  feeling 
aroused,  we  become  strongly  impressed  with  the  truth  that 
subjective  consciousness,  determined  as  it  is  wholly  by  sub- 
jective nature,  state,  and  circumstances,  is  no  measure  of 
objective  existence. 

Indeed,  the  primitive  belief  that  redness  exists  as  such 
out  of  the  mind,  and  that  sound  possesses  apart  from  our- 
selves that  quality  which  it  has  to  our  perception,  is  thus 
rendered  as  hard  for  the  psychologist  to  entertain  as  its 
opposite  is  hard  to  entertain  for  the  uncultivated.  After 
learning  that  when  a  tumbler  is  struck  the  blow  causes 
in  it  a  change  of  form,  instantly  followed  by  an  oppo- 
site change  of  form,  after  which  there  recurs  the  first 
form,  and  so  on — after  perceiving  that  each  of  these  rhyth- 
mical changes  of  form  gives  an  impact  to  substances  in 
contact  with  the  tumbler,  generating  visible  waves  on  the 
surface  of  its  contained  liquid,  and  waves  having  like  periods 
in  the  surrounding  air — when  it  has  been  proved  to  us  that 
the  feeling  of  tone  results  only  when  such  mechanical  oscil- 
lations of  adjacent  matter  recur  with  a  certain  speed,  and 
varies  in  quality  according  to  the  speed — when,  further,  we 
find  that  these  mechanical  oscillations  produce  this  feeling 
only  when  they  fall  on  a  particular  structure,  and  that,  when 
they  fall  on  other  structures,  they  produce  feelings  of 
totally  unlike  kinds;  we  become  fully  convinced  that  the 
form  of  objective  action  we  call  sound,  has  not  the  slightest 
kinship  in  nature  to  the  sensation  of  sound  which  it  arouses 
in  us.  Similarly  with  undulations  of  the  etherial  medium, 
l^ow  that  we  know  heat  and  light  to  be  nearly-allied  forms 
of  insensible  motion,  which  may  arise  by  transformation  of 


206  THE  INDUCTIONS  OF  PSYCHOLOGY. 

sensible  motion  and  may  be  re-transformed  into  it,  we  are 
convinced  that  among  the  outer  actions  which  arouse  in  us 
the  feelings  of  light,  heat,  and  sensible  motion,  there  can  be 
no  such  intrinsic  differences  as  among  the  feelings  we  know 
by  these  names;  and  that  hence  these  feelings  cannot  be 
like  them.  There  follows  irresistibly  the  conclusion  that 
the  same  holds  of  tastes  and  smells — that  a  bitter  flavour 
implies  in  the  substance  yielding  it  nothing  like  what  we 
call  bitterness,  and  that  there  is  no  intrinsic  sweetness  in 
the  exhaled  matter  which  we  distinguish  as  a  sweet  odour; 
but  that,  in  these  cases  as  in  the  others,  the  objective  action 
which  sets  up  the  subjective  state,  no  more  resembles  it 
than  the  pressure  which  moves  the  trigger  of  a  gun  resem- 
bles the  explosion  which  follows. 

Finally,  the  induction  extends  itself  to  the  sensations  of 
tension  and  pressure  which  we  ascribe  to  mechanical  force, 
ordinarily  so-called.  The  same  weight  produces  one  kind 
of  feeling  when  it  rests  on  a  passive  portion  of  the  body, 
and  another  kind  of  feeling  when  supported  at  the  end  of 
the  outstretched  arm.  Or,  to  take  a  better  case — if,  one 
hand  being  opened  out  on  the  table,  a  knuckle  of  the  other 
hand  is  thrust  down  with  some  force  on  the  back  of  it, 
there  results  a  sensation  of  pain  in  the  back  of  the  hand,  a 
sensation  of  pressure  in  the  knuckle,  and  a  sensation  of  mus- 
cular tension  in  the  active  arm.  Which  of  these  sensations 
does  the  mechanical  force  in  action  resemble,  qualitatively 
or  quantitatively?  Clearly,  it  cannot  be  assimilated  to  one 
more  than  another  of  them;  and  hence  must  in  itself  be 
something  alien  from,  or  unrepresentable  by,  any  feeling. 

Thus  we  are  brought  to  the  conclusion  that  what  we  are 
conscious  of  as  properties  of  matter,  even  down  to  its  weight 
and  resistance,  are  but  subjective  affections  produced  by 
objective  agencies  that  are  unknown  and  unknowable.  All 
the  sensations  produced  in  us  by  environing  things  are  but 
symbols  of  actions  out  of  ourselves,  the  natures  of  which 
we  cannot  even  conceive. 


THE  RELATIVITY  OP  FEELINGS.  207 

§  87.  This  conclusion  fully  harmonizes  with,  and  is  in- 
deed an  obvious  corollary  from,  those  truths  which  Physi- 
ology supplies  as  data  to  Psychology.  Let  us  briefly  note 
how  the  structural  and  functional  facts  set  down  in  the  pre- 
ceding part,  yield  deductively  the  inferences  above  reached 
inductively. 

A  nerve  is  a  thread  of  unstable  nitrogenous  substai^ce 
running  from  periphery  to  centre  or  from  centre  to  peri- 
phery, along  which,  when  one  of  its  ends  is  disturbed, 
there  runs  a  wave  of  molecular  change  to  the  other.  The 
wave  of  change  set  up  by  a  peripheral  disturbance  is  not 
like  the  action  which  causes  it;  and  the  waves  of  change  set 
up  in  different  nerves  by  different  peripheral  disturbances 
have  no  such  unlikenesses  as  have  the  disturbances  them- 
selves. Hence  being  obliged  to  conclude  that  the  kind  of 
feeling  depends  either  on  the  character  of  the  nerve-centre, 
or  on  the  way  in  which  the  molecular  disturbance  is 
brought  to  the  nerve-centre,  or  on  both;  it  becomes  incon- 
ceivable that  any  resemblance  exists  between  the  subjective 
effect  and  that  objective  cause  which  arouses  it  through  the 
intermediation  of  changes  resembling  neither. 

Similarly  with  the  quantitative  variations.  Seeing,  as  we 
did,  that  every  nervous  disturbance  propagated  from  peri- 
phery to  centre  undergoes  a  multiplication,  the  degree  of 
which  depends  primarily  on  the  particular  multiplying 
structures  passed  through,  and  secondarily  on  the  changeable 
physiological  conditions  which  favour  or  hinder  the  multipli- 
cation; it  is  clear  that,  if  what  on  its  physical  side  is  a 
central  nervous  disturbance,  is  on  its  psychical  side  a  feel- 
ing, there  cannot  be  constant  proportions  between  feelings 
and  the  environing  stimuli  to  which  they  answer.  Quanti- 
tatively as  well  as  qualitatively,  feeling  must  be  relative  to 
the  nature  and  state  of  the  subject. 

§  88.  But  now  let  us  not  overlook  an  all-important  im- 
plication very  generally  overlooked,  and  the  overlooking  of 


208  THE  INDUCTIONS  OF  PSYCHOLOGY. 

which  leads  to  elaborate  systems  of  erroneous  inferences  of 
very  remarkable,  not  to  say  astonishing,  kinds. 

All  the  foregoing  arguments,  and  all  arguments  of  kin- 
dred natures,  set  out  by  assuming  objective  existence.  Not  a 
step  can  be  taken  towards  the  truth  that  our  states  of  con- 
sciousness are  the  only  things  we  can  know,  without  tacitly 
or  avowedly  postulating  an  unknown  something  beyond  con- 
sciousness. The  proposition  that  whatever  we  feel  has  an 
existence  which  is  relative  to  ourselves  only,  cannot  be 
proved,  nay  cannot  even  be  intelligibly  expressed,  without 
asserting,  directly  or  by  implication,  an  external  existence 
which  is  not  relative  to  ourselves.  When  it  is  argued  that 
what  we  are  conscious  of  as  sound  has  no  objective  reality 
as  such,  since  its  antecedent  is  also  the  antecedent  to  what 
we  are  conscious  of  as  jar,  and  that  the  two  consequents, 
being  unlike  one  another,  cannot  be  respectively  like  their 
common  antecedent;  the  validity  of  the  argument  depends 
wholly  on  the  existence  of  the  common  antecedent  as  some- 
thing that  has  remained  unchanged  while  consciousness 
has  been  changing.  If,  after  finding  that  the  same  tepid 
water  may  feel  warm  to  one  hand  and  cold  to  the  other, 
it  is  inferred  that  warmth  is  relative  to  our  own  nature  and 
our  own  state;  the  inference  is  valid  only  supposing  the 
activity  to  which  these  different  sensations  are  referred,  is 
an  activity  out  of  ourselves  which  has  not  been  modified 
by  our  own  activities. 

One  of  two  things  must  be  asserted: — Either  the  ante- 
cedents of  each  feeling,  or  state  of  consciousness,  exist  only 
as  previous  feelings  or  states  of  consciousness;  or  else  they, 
or  some  of  them,  exist  apart  from,  or  independently  of,  con- 
sciousness. If  the  first  is  asserted,  then  the  proof  that  what- 
ever we  feel  exists  relatively  to  ourselves  only,  becomes 
doubly  meaningless.  To  say  that  a  sensation  of  sound  and 
a  sensation  of  jar  cannot  be  respectively  like  their  common 
antecedent  because  they  are  not  like  one  another,  is  an 
empty  proposition;  since  the  two  feelings  of  sound  and  jar 


THE  RELATIVITY  OP  PEELINGS.  209 

never  have  a  common  antecedent  in  consciousness.  The 
combination  of  feelings  that  is  followed  by  the  feeling 
of  jar,  is  never  the  same  as  the  combination  of  feelings 
that  is  followed  by  the  feeling  of  sound;  and  hence, 
not  having  a  common  antecedent,  it  cannot  be  argued 
that  they  are  unlike  it.  Moreover,  if  by  antecedent  is 
meant  constant  or  uniform  antecedent  (and  any  other 
meaning  is  suicidal)  then  the  proposition  that  the  ante- 
cedent of  sound  exists  only  in  consciousness,  is  abso- 
lutely irreconcilable  with  the  fact  that  the  feeling  of 
sound  often  abruptly  breaks  in  upon  the  series  of  feelings 
otherwise  determined,  where  no  antecedent  of  the  specified 
kind  has  occurred.  The  other  alternative,  there- 

fore, that  the  active  antecedent  of  each  primary  feeling  exists 
independently  of  consciousness,  is  the  only  thinkable  one. 
It  is  the  one  implicitly  asserted  in  the  very  proposition 
that  feelings  are  relative  to  our  own  natures;  and  it  is  taken 
for  granted  in  every  step  of  every  argument  by  which  this 
proposition  is  proved. 

Thus  we  come  once  more  by  another  route  to  the  con- 
clusion already  twice  reached.  In  the  first  part  of  First 
J*rinciples,wlien  treating  of  the  relativity  of  knowledge,  it 
was  shown  that  the  existence  of  a  non-relative  is  unavoid- 
ably asserted  in  every  chain  of  reasoning  by  which  relativity 
is  proved.  In  the  second  part  of  First  Principles,  when 
dealing  with  the  Data  of  Philosophy,  it  was  shown  that  the 
co-existence  of  subject  and  object  is  a  deliverance  of  con- 
sciousness which,  taking  precedence  of  all  analytical  exam- 
ination, but  subsequently  verified  by  analytic  examination, 
is  a  truth  transcending  all  others  in  certainty.  And  here 
again,  the  validity  of  the  conclusion  that  whatever  we  feel 
exists  as  we  feel  it  only  in  ourselves,  we  find  to  depend 
entirely  upon  the  postulate  that  feelings  have  antecedents 
out  of  ourselves. 


CHAPTEK  lY. 

THE   EELATIVITY    OF    RELATIONS    BETWEEN    FEELINGS. 

§  89.  The  mildest  criticism  on  this  title  will  probably  be 
that  it  is  an  awkward  combination  of  words;  and  an  out- 
spoken critic  will  very  likely  condemn  it  either  as  non- 
sensical or  as  meaningless.  !N^evertheless  it  has  a  definite 
meaning  not  properly  expressible  by  any  other  title. 

Mind  we  found  to  be  composed  of  feelings  and  the  rela- 
tions between  feelings.  In  the  last  chapter,  it  was  8ho\^ni 
that  the  kinds  and  amounts  of  feelings  are  determined  by 
the  nature  of  the  subject — exist,  as  we  know  them,  only 
in  consciousness,  and  have  no  resemblance  to  the  agents 
beyond  consciousness  which  cause  them.  And  it  is  the 
purpose  of  this  chapter  to  show  that  in  like  manner  the 
forms  and  degrees  of  relations  between  feelings  are  deter- 
mined by  the  nature  of  the  subject — exist,  as  we  know  them, 
only  in  consciousness,  and  no  more  resemble  the  connexions 
between  outer  agents  than  the  feelings  they  unite  resemble 
these  outer  agents. 

The  most  highly  compounded  relations  between  feel- 
ings, are  those  in  which  they  are  present  to  conscious- 
ness not  simply  as  co-existing  but  as  co-existing  in  certain 
relative  positions — co-existing,  that  is,  along  with  many 
of  those  intervening  and  surrounding  positions  which 
are  the  units  of  our  conception  of  Space.  The  relativity  of 
those  compound  relations  of  Co-existence,  as  we  may  call 

them,  must  be  dealt  with  first.    After  them  we  will  pass  to 

210 


THE  RELATIVITY  OP  RELATIONS.  211 

the  compound  relations  of  Sequence,  or  those  in  which 
feelings  are  known  not  simply  as  having  occurred  in 
succession,  but  as  occupying  certain  positions  in  the  series 
of  states  of  consciousness,  between  which  there  are  inter- 
vening positions  occupied  by  other  states — relations  of 
Sequence,  that  is,  in  which  Time,  regarded  as  having  an 
assignable  quantity,  is  an  element.  We  will  next  consider 
the  compound  relations  of  Difference,  or  those  in  which 
beyond  the  mere  consciousness  of  Difference,  there  is  a 
consciousness  of  the  degree  of  Difference — relations  of 
Difference,  that  is,  in  which  the  related  feelings  are  con- 
ceived as  differing  in  strength  by  assignable  amounts. 
The  relations  of  Co-existence,  of  Sequence,  and  of  Differ- 
ence, considered  under  their  simplest  aspects  apart  from 
quantitative  implications,  may  then  occupy  us. 

§  90.  No  great  effort  of  imagination  is  required  to  see 
that  the  consciousness  of  space  of  three  dimensions,  consti- 
tuted of  trebly-compounded  relations  of  Co-existence,  is  a 
consciousness  that  varies  qualitatively  according  to  the 
structure  of  the  species.  It  needs  but  to  call  to  mind  how 
greatly  our  conception  of  space  is  modified  when  we  are  in 
a  dark  place  of  which  we  know  not  the  bounds,  to  perceive 
that  those  inferior  creatures  which  have  no  eyes,  and  cannot, 
as  we  do  in  the  dark,  supplement  present  tactual  experiences 
by  remembered  visual  experiences,  must  have  concep- 
tions of  space  quite  unlike  in  quality  to  our  own, 
which  are  abstracted  in  so  large  a  degree  from  visual 
experiences.  I^ot  only  must  the  consciousness 

of  trebly-compounded  relations  of  Co-existence  be  quali- 
tatively different  in  such  inferior  creatures,  but  also  those 
of  doubly-compounded  and  singly-compounded  relations  of 
Co-existence.  A  creature  with  eyes  is  capable  of  having 
all  the  relative  positions  constituting  an  area,  impressed 
on  consciousness  with  apparent  simultaneity;  but  a  creature 
without  eyes  can  become  conscious  of  these  multitudinous 
16 


212  THE  INDUCTIONS  OF  PSYCHOLOGY. 

relative  positions  only  through  continued  tactual  explora- 
tions, presenting  most  of  them  in  distinct  succession.  And 
whereas  space  of  one  dimension  is  knowable  by  the  seeing 
creature  as  a  seemingly-instantaneous  consciousness  of  the 
relative  positions  of  two  things  impressing  it,  the  conscious- 
ness of  these  relative  positions  in  a  creature  without  eyes 
(unless  the  things  are  so  close  as  to  be  touched  at  the  same 
instant  by  two  parts  of  the  creature's  body)  cannot  be 
seemingly  instantaneous,  but  must  last  during  the  appreci- 
able period  required  for  muscular  movement  of  a  limb,  or  of 
the  body,  from  one  to  the  other.  Of  course  such  qualitative 
differences  among  compound  relations  of  Co-existence  as 
present  to  consciousness,  must  have  countless  gradations, 
determined  by  the  perfection  of  sight  and  the  range  of 
sight.  It  may  be  added  that  there  is  even  a 

species  of  qualitative  variation  that  occurs  in  the  same 
creature  using  the  same  senses.  Take  two  objects  suf- 
ficiently far  apart  to  give  standing  room  between  them. 
Having  contemplated  their  relation  of  position  from  a 
distance,  contemplate  it  afresh  after  having  so  placed  the 
body  that  one  of  them  is  in  front  and  one  of  them  is  behind. 
It  will  be  found  that  what  is  conceived  as  a  single  relation 
in  the  one  case  cannot  be  so  conceived  in  the  other.  While 
standing  between  the  two  objects,  it  is  possible  to  think  of 
their  relative  positions  only  by  thinking  successively  of  their 
two  relations  of  position  with  self.  That  com- 

pound relations  of  Co-existence  as  conceived  by  different 
species,  vary  quantitatively  with  the  structures  of  the  species, 
seems,  to  say  the  least,  very  probable.  Animals  having 
great  locomotive  powers  are  not  likely  to  have  the  same 
conceptions  of  given  spaces  as  animals  whose  locomotive 
powers  are  very  small.  To  a  creature  so  constructed  that  its 
experiences  of  the  larger  spaces  around  have  been  gained 
by  long  and  quick  bounds,  distances  can  scarcely  present 
the  aspects  they  do  to  a  creature  which  traverses  them  by 
slow  and  many  steps. 


THE  RELATIVITY  OP  RELATIONS.  213 

The  dimensions  of  our  bodies  and  the  spaces  moved 
through  by  our  limbs,  serve  us  as  standards  of  comparison 
with  environing  dimensions;  and  conceptions  of  smallness 
or  largeness  result  according  as  these  environing  dimensions 
are  much  less  or  much  greater  than  the  organic  dimensions. 
Hence,  the  consciousness  of  a  given  relation  of  two  positions 
in  space,  must  vary  quantitatively  with  variation  of 
bodily  bulk.  Clearly,  a  mouse,  which  has  to  run  many 
times  its  own  length  to  traverse  the  space  which  a  man 
traverses  at  a  stride,  cannot  have  the  same  conception  of 
this  space  as  a  man.  Quantitative  changes  in  these  com- 
pound relations  of  Co-existence  are  traceable  by  each  person 
in  his  own  mental  history,  from  childhood  to  maturity. 
Distances  which  seemed  great  to  the  boy  seem  moderate 
to  the  man;  and  buildings  once  thought  imposing  in  height 
and  mass,  dwindle  into  insignificance. 

The  physiological  state  of  the  organism  also  modifies 
quantitatively  this  form  of  consciousness  to  a  considerable 
extent.  De  Quincey,  describing  some  of  his  opium-dreams, 
says  that  "  buildings  and  landscapes  were  exhibited  in  pro- 
portions so  vast  as  the  bodily  eye  is  not  fitted  to  receive. 
Space  swelled,  and  was  amplified  to  an  extent  of  unutterable 
infinity."  It  is  not  an  uncommon  thing  with  nervous 
subjects  to  have  illusive  perceptions  in  which  the  body 
seems  enormously  extended:  even  to  the  covering  an  acre 
of  ground. 

A  more  special  modification  of  bodily  state  also  affects  the 
conception.  Like  all  other  nervous  structures,  the  nervous 
structures  employed  in  the  apprehension  of  space  have  their 
receptivity  temporarily  diminished  by  action.  As  the  appreci- 
ation of  a  delicate  taste  is  hindered  when  the  palate  has  just 
been  excited  by  a  very  strong  taste ;  so  a  small  or  moderate 
magnitude  is  under-estimated  when  a  great  magnitude  has 
just  before  occupied  the  attention.  A  building  that  appeared 
large  when  it  stood  amid  smaller  buildings,  loses  much  of  its 
seeming  largeness  if  a  far  larger  building  is  erected  close 


214:  THE  INDUCTIONS  OF   PSYCHOLOGY. 

to  it.  Or,  to  take  a  better  case — when  the  Sun  is  seen  in  the 
midst  of  the  sky,  with  none  but  great  angular  spaces 
between  it  and  the  horizon,  it  looks  very  much  less  than  it 
does  when  close  to  the  horizon,  where  the  angular  space  it 
subtends  is  comparable  side  by  side  with  small  angular 
spaces. 

Yet  again,  compound  relations  of  Co-existence  vary  with 
the  position  of  the  observer,  not  only  quantitatively,  but,  in 
a  certain  sense,  qualitatively;  for  so  only  can  we  express 
the  truths  that  apparent  size  depends  on  distance  from  the 
eye,  and  that  apparent  form  changes  with  every  change  in 
the  point  of  view.  The  impressions  made,  on  us 

by  two  objects  to  both  of  which  we  are  close,  are  consider- 
ably removed  from  one  another  in  consciousness.  But  as 
we  recede  from  such  two  objects,  that  compound  relation  of 
Co-existence  which  forms  our  conception  of  their  relative 
positions,  diminishes  quantitatively,  and  at  last  disappears 
altogether:  the  two  impressions  they  give  us  merge  into 
one.  The  facts  that  the  co-existent  positions  forming 

a  circle  become  to  perception  an  ellipse  when  viewed 
obliquely,  and  a  straight  line  when  viewed  edgeways, 
illustrate  the  truth  that  compound  relations  of  Co-existence 
undergo  a  species  of  qualitative  variation  as  the  place  of  the 
percipient  varies.  This  kind  of  variation  is  doubtless  due 
to  differences  among  the  rates  of  quantitative  variation  of 
the  many  component  relations ;  but  it  is  none  the  less  to  be 
regarded  as  a  qualitative  variation,  since  differences  of 
quality  in  general  are  resolvable  into  differences  in  the 
ratios  of  the  co-operative  factors. 

We  are  thus  driven  to  the  conclusion  that  what  we  con- 
ceive as  space-relations,  cannot  be,  either  in  their  natures  or 
degrees,  like  those  connexions  among  external  things  to 
which  they  are  due.  They  change  both  qualitatively  and 
quantitatively  with  the  structure,  the  size,  the  state,  and 
the  position,  of  the  percipient.  And  when  we  see  that  what 
is,   objectively  considered,   the  same  connexion  between 


THE  RELATIVITY  OF  RELATIONS.  215 

things,  may,  as  a  space-relation  in  consciousness,  be  single 
or  double — when  we  remember  that,  according  as  we  are 
near  or  far  off,  it  may  be  too  large  to  be  simultaneously 
perceived  or  too  small  to  be  perceived  at  all;  it  becomes 
impossible  to  suppose  any  identity  between  this  objective 
connexion  and  some  one  of  the  multitudinous  subjective 
relations  answering  to  it. 

§  91.  The  compound  relations  of  Sequence,  or  those  in 
which  we  conceive  phenomena  as  having  occurred,  not 
simply  one  after  another,  but  as  occupying  places  in  con- 
sciousness between  which  there  are  intervals  measured  by 
intervening  places,  and  from  which,  by  abstraction,  we 
derive  our  conception  of  Time,  do  not  at  first  sight  appear 
to  vary  qualitatively.  Reasons  may,  however,  be  assigned 
for  suspecting  qualitative  variations  in  them. 

Such  qualitative  variations  as  probably  occur,  are  deter- 
mined by  differences  of  specific  structure.  A  stationary 
creature  without  eyes,  receiving  distinct  sensations  from 
external  objects  only  by  contacts  which  happen  at  long  and 
irregular  intervals,  cannot  have  in  its  consciousness  any 
compound  relations  of  sequence  save  those  arising  from  the 
slow  rhythm  of  its  functions.  Even  in  ourselves  the  respi- 
ratory intervals,  joined  sometimes  with  the  intervals  between 
the  heart's  pulses,  furnish  part  of  the  materials  from  which 
our  consciousness  of  duration  is  derived;  and  had  we  no 
continuous  perceptions  of  external  changes,  and  conse- 
quently no  ideas  of  them,  these  rhythmical  organic  actions 
would  obviously  yield  important  data  for  our  consciousness 
of  Time :  indeed,  in  the  absence  of  locomotive  rhythms,  our 
sole  data.  Remembering  this,  and  remembering  that  the 
sequences  with  which  we  are  chiefly  occupied,  and  from 
which  our  conception  of  Time  is  chiefly  abstracted,  are  not 
these  sequences  derived  from  internal  actions,  but  the  se- 
quences in  our  impressions  of  external  actions,  it  will  be 
manifest  that  there  is  most  likely  a  marked  qualitative 


216  THE  INDUCTIONS  OF  PSYCHOLOGY. 

difference  between  that  undeveloped  sense  of  duration 
derived  solely  from  the  experiences  of  inner  changes,  and 
that  developed  conception  of  Time  derived  mainly  from 
outer  changes,  but  conceived  to  be  a  form  of  both 
outer  and  inner  changes.  Quantitative 

variations  in  compound  relations  of  Sequence  as  existing 
in  consciousness,  are  manifestly  caused  by  the  struc- 
tural differences  which  constitute  differences  of  species. 
Subjective  rhythms,  partly  of  the  vital  functions  and  partly 
of  the  locomotive  functions,  mark  out  consciousness 
into  tolerably  regular  intervals;  thus  yielding  measures 
between  states  of  consciousness  otherwise  caused — standards 
of  duration.  Hence  a  small  creature,  in  which  these 
rhythms  are  very  rapid,  must  have  a  consciousness  of  a 
given  objective  interval  widely  unlike  the  consciousness 
of  it  possessed  by  a  large  animal,  whose  rhythms  are  rela- 
tively very  slow.  A  gnat's  wings  make  ten  or  fifteen  thou- 
sand strokes  per  second.  Each  stroke  implies  a  separate 
nervous  action.  Each  such  nervous  action,  or  change 
in  a  nervous  centre,  is  probably  as  appreciable  by  the  gnat 
as  is  a  quick  movement  of  his  arm  by  a  man.  And  if  this, 
or  anything  like  this,  is  the  fact,  then  the  time  occupied 
by  a  given  external  change,  measured  by  many  movements 
in  the  one  case,  must  seem  much  longer  than  it  seems  in  the 
other  case,  when  measured  by  a  single  movement. 

How  age  determines  quantitative  variations  in  compound 
relations  of  Sequence,  is  a  matter  of  common  remark.  Pro- 
bably these  are  in  part  due  to  differences  of  size,  and  con- 
comitant differences  in  the  rhythms  of  the  functions,  vital 
and  locomotive:  it  requires  a  greater  number  of  a  child's 
movements  than  of  a  man's  movements  to  measure  a  day. 
But  that  the  change  in  the  estimation  of  intervals  is  not 
wholly  thus  caused,  is  manifest  from  the  fact  that  after 
maturity  is  reached,  they,  or  at  any  rate  the  longer  ones, 
continue  to  undergo  a  seeming  abbreviation.  Months  to  the 
old  man  appear  no  longer  than  weeks  to  the  young  man. 


TflJi:  KJULATiViTY  OF  RELATIONS.  21? 

A  further  quantitative  variation,  essentially  similar  in 
origin  to  that  which  takes  place  with  advancing  years, 
accompanies  variation  in  external  circumstances,  when  this 
increases  or  decreases  the  number  of  vivid  experiences 
within  a  given  interval.  If,  after  a  monotonous  life,  a 
journey  of  pleasure  brings  within  a  week  many  exciting 
novelties,  the  remark  habitually  made  is,  that  it  seems  far 
more  than  a  week  since  home  scenes  were  left  behind. 
Even  a  comparatively  monotonous  state  of  consciousness 
appears  long  if  it  is  intense :  instance  the  time  during  which 
a  severe  pain  is  suffered;  or  instance  an  interval  of  impatient 
expectation,  the  seeming  length  of  which  is  popularly  illus- 
trated by  the  proverb — "  The  watched  pot  never  boils." 

The  estimation  of  Time  varies  also  with  the  constitutional 
state.  Whatever  exalts  the  vital  activities,  and  so  makes 
mental  impressions  stronger,  exaggerates  the  conceptions  of 
durations.  This  is  notably  the  case  in  persons  under  the 
influence  of  opium.  Detailing  his  experiences  of  this  influ- 
ence, De  Quincey  says  that  he  sometimes  seemed  "  to  have 
lived  for  70  or  100  years  in  one  night;  "  nay,  to  have  had 
"  feelings  representative  of  a  millennium  passed  in  that 
time,  or,  however,  of  a  duration  far  beyond  the  limits  of 
any  human  experience." 

One  more  cause  of  quantitative  variation  in  the  conscious- 
ness of  a  compound  relation  of  Sequence,  is  change  of 
position  among  our  experiences.  Intervals  of  Time,  like 
intervals  of  Space,  become  apparently  small  in  proportion 
to  their  remoteness.  An  evening  spent  at  a  friend's  house, 
seems  of  considerable  length  when  looked  back  upon  at  the 
moment  of  departure.  When  recalled  a  week  after,  it 
subtends  by  no  means  so  great  an  angle  in  consciousness; 
and  the  angle  it  subtends  in  consciousness  when  we  are 
reminded  of  it  a  year  after,  is  very  small.  There  is  a  con- 
viction that  it  was  several  hours  long;  but  when  contem- 
plated it  cannot  be  made  of  equal  apparent  length  with  the 
several  hours  just  passed,  any  more  than  the  apparently-small 


218  THE  INDUCTIONS  OP  PSYCHOLOGY. 

distance  between  two  objects  on  the  horizon,  can  be  made 
in  actual  perception  like  the  great  interval  which  appeared 
between  them  when  we  saw  them  close  at  hand.  In  other 
words,  there  is  a  fore-shortening  of  protensive  quantity 
analogous  to  the  fore-shortening  of  extensive  quantity; 
whence  it  results  that  the  intervals  between  passing  ex- 
peciences  begin  to  seem  less  as  soon  as  they  are  past,  and 
continually  dwindle  as  we  get  further  from  them,  until  at 
last  their  lengths  become  inappreciable.  To  this  law  of 
mental  perspective  is  due  the  fact  that,  in  retrospect,  life 
seems  no  longer  at  forty  than  it  did  at  twenty. 

Hence,  concerning  compound  relations  of  Sequence,  as 
concerning  compound  relations  of  Co-existence,  we  must  say 
that  probably  they  are  not  qualitatively  like  the  connexions 
to  which  they  answer,  and  certainly  they  are  not  quanti- 
tatively like  them.  For  suspecting  that  whatever 
objectively  originates  our  subjective  conception  of  Time,  is 
not  identical  in  nature  with  it,  we  have  the  reason  that  Time, 
considered  as  an  abstract  from  relations  of  Sequence,  must 
present  a  different  aspect  according  to  the  degree  of  its  dis- 
sociation from  particular  sequences.  To  a  lowly-endowed 
creature,  conscious  only  of  internally-initiated  changes,  it 
cannot  appear  what  it  does  to  a  creature  chiefly  occupied 
with  changes  that  are  externally  initiated ;  since,  in  the  last, 
it  is  partially  dissociated  from  both  orders  of  changes. 
Whence  it  seems  inferable  that,  only  partially  dissociated 
as  it  is,  it  cannot  have  in  consciousness  that  qualitative 
character  which  absolute  dissociation  would  give  it,  and 
which  we  must  suppose  it  to  have  objectively.  And 
that  compound  relations  of  Sequence  as  we  conceive  them, 
cannot  be  quantitatively  like  the  connexions  beyond 
consciousness  to  which  they  refer,  is  proved  by  the  fact  that 
they  vary  in  their  apparent  lengths  with  the  structure  of  the 
organism,  with  its  size,  with  its  age,  with  its  constitutional 
state,  with  the  number  and  vividness  of  the  impressions 
it  receives,  and  with  their  relative  positions  in  consciousness. 


THE  RELATIVITY  OF  RELATIONS.  219 

Manifestly,  as  no  one  of  these  variously-estimated  lengths 
can  be  taken  as  valid  rather  than  the  others,  it  becomes 
impossible  to  suppose  equality  between  an  interval  of  time 
as  present  to  consciousness  and  any  nexus  of  things  which 
it  symbolizes. 

§  92.  Deeper  than  the  compound  relations  of  Co- 
existence and  Sequence,  is  the  compound  relation  of 
Difference;  since,  besides  being  involved  in  the  comparisons 
of  spaces  and  of  times,  this  is  involved  in  comparisons  of 
the  Forces  manifested  in  Space  and  Time.  We  may  fitly 
limit  ourselves  to  illustrations  taken  from  this  last  class  of 
cases. 

As  into  a  conception  of  two  things  co-existing  at  an 
assignable  distance  apart,  there  enters  the  consciousness 
of  many  or  few  co-existing  positions  between  them;  and  as 
into  the  conception  of  two  changes  separated  by  an  assign- 
able interval  of  time,  there  enters  the  consciousness  of  many 
or  few  intervening  sequent  positions;  so  into  the  conception 
of  two  forces  that  have  an  assignable  inequality,  there 
enters  the  consciousness  of  many  or  few  degrees  of  difference; 
and  the  conceived  amount  of  difference  is  determined  by  the 
number  of  these  degrees.  What  we  have  here  to  observe 
is,  that  our  conceptions  of  amounts  of  difference,  so  con- 
stituted, have  relativities  analogous  to  those  which  exist  in 
our  conceptions  of  amounts  of  spaces  and  amounts  of  times. 

That  the  compound  relation  of  Difference  varies  qualita- 
tively according  to  the  structure  of  the  species,  we  have  no 
distinct  evidence.  But  since  a  compound  relation  of  Dif- 
ference has  to  be  conceived  in  terms  of  impressions  that 
differ;  and  since  the  conception  of  Difference  cannot  be 
dissociated  from  the  order  of  impressions  in  which  it  is 
presented,  if  there  is  but  one  such  order;  it  may  be  inferred 
that,  in  proportion  as  the  impressions  become  more  multi- 
tudinous in  their  kinds,  the  conception  of  Difference 
becomes  more  independent  of  particular  differences;    and 


THE  INDUCTIONS  OP  PSYCHOLOGY. 

that,  therefore,  in  higher  creatures  it  is  not  qualitatively 
the  same  as  in  lower  creatures. 

That  quantitative  variations  in  the  conception  accompany 
specific  unlikenesses  of  structure,  becomes  manifest  when  it 
is  remembered  that  a  difference  in  forces  does  or  does  not 
give  rise  to  a  difference  in  feelings,  according  as  the  or- 
ganization is  or  is  not  highly  recipient.  Incident  forces 
that  seem  alike  to  a  lowly-endowed  creature,  seem  conspicu- 
ously unlike  to  a  creature  endowed  with  the  sense-organs 
required  for  appreciating  them.  Where  eyes  are  so  little 
developed  that  approaching  objects  are  recognized  only  as 
intercepting  the  sunshine,  it  is  obvious  that  contrasts  of 
light  and  shade  which  seem  marked  to  animals  with  de- 
veloped eyes,  are  quite  imperceptible.  Similarly  among 
highly-endowed  animals  of  diverse  kinds.  Between  odours 
both  of  which  produce  in  a  man  no  impression  whatever,  a 
dog  perceives  differences  of  strength,  probably  of  many 
degrees.  Even  the  structural  unlikenesses  of  individuals 
entail  such  results.  A  good  ear  detects  several  gradations 
between  tones  which  to  a  bad  ear  seem  alike. 

The  bulk  of  the  organism  is  also  a  factor  in  modifying 
quantitatively  the  relation  of  Difference.  The  manifesta- 
tions of  force  between  which  a  creature  can  perceive  un- 
likenesses, are  limited  at  the  one  extreme  by  its  ability  to 
bear  them  and  at  the  other  extreme  by  its  capacity  for 
being  sensibly  affected  by  them;  and  its  size  partly  deter- 
mines these  limits.  A  grain  and  half-a-grain  are  hardly 
distinguishable  by  their  pressures  on  the  finger;  but  if  suc- 
cessively borne  by  an  animal  not  more  than  a  grain  in 
weight,  a  difference  divisible  into  many  degrees  would 
doubtless  be  perceptible  between  them.  Conversely,  a  man 
cannot  perceive  the  contrast  in  weight  between  a  ton  and 
half-a-ton,  for  he  fails  to  put  forth  a  force  sufficient  to  lift 
either;  but  it  can  scarcely  be  questioned  that  in  the  con- 
sciousness of  an  elephant,  now  loaded  with  one  and  now 
with  the  other,  the  feelings  produced  would  have  an  unlike* 


THE  RELATIVITY  OP  RELATIONS.  221 

ness  that  might  begraduated.  Objective  differences,  all  equal 
in  degree,  are  thus  manifestly  appreciable  by  any  creature 
only  within  a  range  that  is  really  very  narrow.  More- 

over, it  is  demonstrable  that  towards  either  extremity 
of  this  range,  the  conceptions  of  Difference  become 
quantitatively  more  and  more  vague;  and  nowhere 
throughout  the  range  can  there  be  maintained  a  parallelism 
between  the  contrasts  of  inner  feelings  and  the  contrasts  of 
outer  forces  to  which  they  refer.  For  when  a  mass  is 
poised  in  the  hand,  certain  muscles  are  strained  to  the 
degree  required  to  support  the  mass  phis  the  arm.  If  the 
weight  of  the  mass  is  small,  the  weight  of  the  arm  becomes 
the  larger  part  of  the  force  to  be  antagonized;  while  if  the 
mass  is  large,  the  weight  of  the  arm  becomes  the  smaller 
part.  Clearly,  then,  the  effort  put  forth  for  the  support  of 
the  arm  being  a  constant  element  in  the  compared  states  of 
consciousness,  must  modify  the  seeming  difference  between 
weights  to  a  different  extent  according  as  the  absolute 
amounts  of  the  weights  are  increased  or  decreased. 

How  variations  of  constitutional  state,  whether  deter- 
mined by  disorder  or  by  age,  also  cause  quantitative  varia- 
tions in  the  relations  of  Difference  as  conceived  by  us,  need 
not  be  shown  in  detail.  It  is  obvious  from  what  has  been 
said  that  all  exaltations  and  depressions  of  energy  and  of 
sensibility,  must  alter  the  range  v/ithin  which  differences 
are  appreciable,  and  must  modify  the  appreciations  of  them: 
more  especially  towards  each  extreme  of  the  range. 

We  conclude,  then,  that  the  compound  relation  of  Differ- 
ence as  we  know  it,  is  dependent  on  structure,  on  size,  and 
on  constitutional  state.  The  same  objective  difference  may 
have  no  subjective  difference  answering  to  it,  because  the 
forces  between  which  it  exists  are  either  excessive  or 
defective  in  amount.  "Within  the  limits  of  appreciation,  the 
same  objective  difference  may  seem  great  or  small  according 
to  the  percipient's  nature  and  temporary  condition.  And 
as  we  cannot  fix  on  any  one  of  these  relations  in  conscious- 


222  THE  INDUCTIONS  OP  PSYCHOLOGY. 

ness,  rather  than  any  other,  as  like  the  reality  beyond  con- 
sciousness, we  must  infer  that  there  is  no  likeness  between 
any  one  of  them  and  the  reality  beyond  consciousness. 

§  93.  But  now  what  are  we  to  say  about  the  pure 
relations  of  Co-existence,  of  Sequence,  and  of  Difference; 
considered  apart  from  amounts  of  Space,  of  Time,  and  of 
Contrast?  Can  we  say  that  the  relation  of  Co-existence, 
conceived  simply  as  implying  two  terms  that  exist  at  the 
same  time,  but  are  not  specified  in  their  relative  positions, 
has  anything  answering  to  it  beyond  consciousness?  Can 
we  say  that  out  of  ourselves  there  is  such  a  thing  as  Suc- 
cession, corresponding  to  the  conception  we  have  of  one 
thing  coming  after  another,  without  reference  to  the  time 
between  them?  And  can  we  say  that  what  we  know  as 
Difference,  apart  from  any  particular  degree  of  it,  has 
objective  unlikeness  as  its  cause? 

The  reply  is  that  we  cannot  frame  ideas  of  Co-existence, 
of  Sequence,  and  of  Difference,  without  there  entering  into 
them  ideas  of  quantity.  Though  we  have  examined  apart 
the  compound  relations  of  these  orders,  into  which  con- 
sciousness of  quantity  avowedly  enters;  and  though,  in 
above  defining  the  simple  relations  of  these  orders,  the 
avowed  contemplation  of  quantity  is  excluded;  yet,  on 
looking  closely  into  the  matter,  we  find  that  a  tacit  recog- 
nition of  quantity  is  always  present.  Co-existence  cannot 
be  thought  of  without  some  amount  of  space.  Sequence 
cannot  be  thought  of  without  some  interval  of  time. 
Difference  cannot  be  thought  of  without  some  degree  of 
contrast.  Hence  what  has  been  said  above  respecting  these 
relations  in  their  definitely-compound  forms,  applies  to 
them  under  those  forms  which,  by  a  fiction,  we  regard  as 
simple.  All  the  proofs  of  relativity  that  held  where  the 
conceived  quantities  were  large,  hold  however  small  the 
conceived  quantities  become.  And  as  the  conceived  quan- 
tities cannot   disappear   from   consciousness   without  the 


THE  RELATIVITY  OF  RELATIONS.  223 

relations  themselves  disappearing,  it  follows  inevitably  that 
the  relativities  hold  of  the  relations  themselves  in  their 
ultimate  elements.  We  are  thus  forced  to  the  conclusion 
that  the  relations  of  Co-existence,  of  Sequence,  and  of 
Difference,  as  we  know  them,  do  not  obtain  beyond  con- 
sciousness. 

Let  us  simplify  the  matter  by  reducing  derivative  rela- 
tions to  the  fundamental  relation;  and  we  shall  then  see 
more  clearly  the  truth  of  this  apparently-incredible  pro- 
position. 

Every  particular  relation  of  Co-existence  involves  a  cogni- 
tion of  some  difference  in  the  positions  of  the  things  co-exist- 
ing; resolvable,  ultimately,  into  differences  of  relative  posi- 
tion towards  self.  And  differences  of  relative  position  can 
be  known  only  through  differences  between  the  states  of  con- 
sciousness accompanying  the  disclosure  of  the  positions.  But 
while  positions  in  Space,  and  co-existing  objects  occupying 
them,  are  known  through  relations  of  Difference  between 
the  feelings  accompanying  disclosure  of  them;  they  are 
known  through  relations  of  Likeness,  in  respect  of  their 
order  of  presentation.  The  relation  of  Co-existence,  which 
is  that  out  of  which  all  Space-conceptions  are  built,  is  one 
in  which  neither  term  is  first  or  last;  the  terms  exhibit 
equality  in  their  order — no  difference  in  their  order. 

Phenomena  occurring  in  succession,  like  those  occurring 
simultaneously,  are  known  as  occupying  different  positions 
in  consciousness.  Intervals  between  them  are  distinguished 
by  differences  in  the  feelings  that  arise  in  passing  over  the 
intervals;  and  where  the  intervals  are  alike,  they  are  so 
classed  from  the  absence  of  such  differences.  But  while  the 
relations  among  phenomena  in  Time  are  known  as  such  or 
such  through  conceptions  of  Difference  and  No-difference 
yielded  by  comparisons  of  them,  they  are  known  as  alike  in 
this,  that  their  terms  are  unequal  in  order  of  presentation — 
differ  in  their  order. 

Thus  all  Space-relations  and  Time-relations — all  relations 


224  THE  INDUCTIONS  OP  PSYCHOLOGY. 

of  Co-existence  and  Sequence,  are  known  through  relations 
of  Difference  and  No-difference.  Sequence  is  Difference  of 
order;  Co-existence  is  No-difference  of  order.  Hence  we 
have  at  last  to  deal  with  the  relations  of  Difference  and 
No-difference.  And  our  entire  consciousness  being  built 
up  of  feelings  which  present  these  relations,  both  in  them- 
selves and  in  the  secondary  feelings  constituting  conscious- 
ness of  their  order,  the  whole  question  of  the  relativity  of 
relations  among  feelings  is  reducible  to  the  question  of  the 
relativity  of  the  relation  of  Difference.  This  is  readily 
demonstrable. 

The  sole  elements,  and  the  indissoluble  elements,  of  the 
relation  are  these: — A  feeling  of  some  kind;  a  feeling 
coming  next  to  it,  which,  being  distinguishable  as 
another  feeling,  proves  itself  to  be  not  homogeneous  with 
the  first;  a  feeling  of  shock,  more  or  less  decided,  accom- 
panying the  transition.  This  shock,  which  arises  from  the 
difference  of  the  two  feelings,  becomes  the  measure  of  that 
difference — constitutes  by  its  occurrence  the  consciousness 
of  a  relation  of  difference,  and  by  its  degree  the  conscious- 
ness of  the  amount  of  difference.  That  is,  the  relation  of 
Difference  as  present  in  consciousness  is  nothing  more 
than  a  change  in  consciousness.  How,  then,  can  it 
resemble,  or  be  in  any  way  akin  to,  its  source  beyond 
consciousness?  Here  are  two  colours  which  we  call 
unlike.  As  they  exist  objectively,  the  two  colours  are 
quite  independent — there  is  nothing  between  them  answer- 
ing to  the  change  which  results  in  us  from  contemplating 
first  one  and  then  the  other.  Apart  from  our  conscious- 
ness they  are  not  linked  as  are  the  two  feelings  they  pro- 
duce in  us.  Their  relation  as  we  think  it,  being  nothing 
else  than  a  change  of  our  state,  cannot  possibly  be  parallel 
to  anything  between  them,  when  they  have  both  remained 
unchanged. 

§  94.  It  is  proper  to  point  out  that  all  these  conclusions, 


THE  RELATIVITY  OF  RELATIONS.  225 

down  to  the  last  of  them,  are  in  harmony  with  those  which 
may  be  directly  deduced  from  the  data  supplied  by  Physio- 
logy to  Psychology. 

Each  feeling  being  the  concomitant  of  some  molecular 
change  in  a  portion  of  vesicular  nerve-matter;  and  each 
relation  being  the  concomitant  of  some  wave  of  molecular 
transformation  propagated  along  a  nerve-fibre,  or  fibres, 
from  one  portion  of  vesicular  nerve-matter  to  another;  it 
results,  in  the  first  place,  that  the  various  relations  as 
we  know  them  are  composed  of  elements  essentially  alike; 
and  it  results,  in  the  second  place,  that  not  being  in- 
trinsically different  in  their  ultimate  natures,  they  cannot 
resemble  intrinsically-different  objective  connexions. 

Indeed,  it  needs  but  to  think  for  an  instant  of  a  brain  as 
a  seat  of  nervous  discharges,  intermediate  between  actions  in 
the  outer  world  and  actions  in  the  world  of  thought,  to  be 
impressed  with  the  absurdity  of  supposing  that  the  con- 
nexions among  outer  actions,  after  being  transferred  through 
the  medium  of  nervous  discharges,  can  re-appear  in  the 
world  of  thought  in  the  forms  they  originally  had. 

§  95.  But  here  let  us  not  omit  to  recognize  the  assump- 
tion made  throughout,  and  inevitably  made  in  all  reason- 
ing used  to  prove  the  relativity  of  relations,  that  there 
exist  beyond  consciousness,  conditions  of  objective  mani- 
festation which  are  symbolized  by  relations  as  we  conceive 
them. 

The  very  proposition  that  what  we  know  as  a  relation 
is  qualitatively  and  quantitatively  determined  by  our  own 
nature,  and  does  not  resemble  any  order  or  nexus  beyond 
consciousness,  implies  that  there  exists  some  such  order  or 
nexus  beyond  consciousness;  and  every  step  in  every  argu- 
ment by  which  this  proposition  is  established,  distinctly 
posits  this  order  or  nexus,  and  cannot  be  taken  on  any 
other  condition.  Further,  the  argument  assumes,  and  is 
obliged  to  assume,  fundamental  differences  of  objective 


326  THE  INDUCTIONS  OF  PSYCHOLOGY. 

order  which  are  symbolized  by  fundamental  differences  of 
subjective  order. 

For  to  say  that  what  we  know  as  a  relation  between 
positions  in  Space,  cannot  be  like  any  objective  nexus,  since 
this  relation  of  positions  as  conceived  by  us  varies  inde- 
finitely, is  to  say  that  there  exists  an  objective  nexus  which 
has  not  varied.  Two  verdicts  of  consciousness  respecting 
a  given  magnitude  are  found  to  be  unlike  under  unlike 
conditions  of  perception ;  whence  it  is  inferred  that  neither 
of  them  is  like  the  magnitude.  But  the  inference  is  nonsense 
if  by  this  magnitude  is  meant  something  in  consciousness, 
instead  of  something  beyond  consciousness.  As  it  was  before 
shown  in  the  case  of  feelings,  so  it  might  here  be  shown  in 
the  case  of  relations  between  feelings,  the  reasoning  used 
becomes  both  false  in  its  premises  and  meaningless  in  its 
conclusion.  Of  course,  changing  the  terms,  the 

like  holds  with  periods  of  Time.  Every  argument  proving 
that  our  conceptions  of  Time  are  relative,  falls  to  pieces  on 
withdrawing  the  assumption  that  there  exists  some  form  of 
Things  from  which  Time,  as  a  form  of  Thought,  is  derived. 

The  assumption  of  an  objective  source  for  the  subjective 
relation  of  Difference,  is  implied  in  the  last  two  assumptions. 
If,  as  shown  above,  all  special  cognitions  of  spaces  and 
times  involve  cognitions  of  differences;  and  if,  as  shown 
above.  Space  in  general,  which  is  resolvable  into  relations 
of  Co-existence,  and  Time  in  general,  which  is  resolvable  into 
relations  of  Sequence,  are  separable  from  one  another  as 
being  respectively  constituted,  the  last  by  difference  of 
order,  and  the  first  by  no-difference  of  order;  it  is  clear  that 
the  postulation  of  objective  sources  of  these  subjective  forms, 
implies  postulation  of  an  objective  source  of  Difference. 
And  this  postulation  of  an  objective  source  of  Difference, 
equally  implied  in  all  the  arguments  which  prove  the 
relativity  of  the  conception  of  Difference,  has  for  its  ulti- 
mate warrant  the  deepest  assignable  warrant — the  Persist- 
ence of  Force.    Though  the  relation  of  Difference,  consti- 


THE  RELATIVITY  OF  RELATIONS.  227 

tuted,  as  we  have  seen,  by  a  change  in  consciousness,  cannot 
be  identified  with  anything  beyond  consciousness;  yet  that 
there  is  something  beyond  consciousness  to  which  it  is  due, 
is  an  inevitable  conclusion;  since  to  think  otherwise  is  to 
think  of  change  taking  place  without  an  antecedent. 

More  certain,  then,  than  the  Relativity  of  Relations  as 
we  conceive  them,  is  the  existence  of  !Non-relative  Eorms 
to  which  they  refer;  since  proof  of  the  first  involves  per- 
petual assumption  of  the  last.  There  is  some  ontological 
order  whence  arises  the  phenomenal  order  we  know  as 
Space;  there  is  some  ontological  order  whence  arises  the 
phenomenal  order  we  know  as  Time;  and  there  is  some 
ontological  nexus  whence  arises  the  phenomenal  relation  we 
know  as  Difference. 


16 


CHAPTER  V. 

THE    EEVIVABrLITY    OF    FEELINGS. 

§  96.  As  was  pointed  out  in  the  second  chapter  of 
this  part,  Feelings  admit  of  a  double  classification.  On 
grounds  of  structure  they  are  divisible  into  the  centrally- 
initiated  and  the  peripherally-initiated;  which  last  are 
re-divisible  into  those  which  are  peripherally  initiated  by 
external  actions  and  those  which  are  peripherally  initiated 
by  internal  actions.  And  on  grounds  of  function  they  are 
divisible  by  a  line  crossing  these  transversely,  into  those 
primary  or  vivid  feelings  produced  by  direct  excitations, 
and  those  secondary  or  faint  feelings  produced  by  indirect 
excitations.  The  one  class,  known  as  sensations,  are  some- 
times called  presentative  feelings;  and  the  other  class, 
known  as  ideas  (though  this  word  is  more  commonly 
applied  to  clusters  of  them),  are  sometimes  called  re-pre- 
sentative  feelings. 

Thus  far  little  regard  has  been  paid  to  this  grouping  of 
feelings  which  has  in  view  not  difference  of  kind  but  differ- 
ence of  degree.  Though  throughout  the  last  two  chapters, 
we  have  tacitly  recognized  the  distinction — though,  in  deal- 
ing with  the  relativities  of  feelings  and  of  relations,  we  have 
been  obliged  to  take  for  granted  an  established  connexion 
between  the  vivid  feelings  or  sensations  directly  presented 
and  the  faint  feelings  or  ideas  in  which  they  are  represented, 
yet  no  definite  statements  have  been  made  respecting  the 


THE  REVIVABILITY  OF  PEELINGS.  229 

dependence  of  the  second  class  on  the  first.  Here  we  have 
to  inquire  how,  when  vivid  forms  of  feelings  have  been  ex- 
perienced, it  happens  that  faint  forms  of  feelings  like  them 
afterwards  arise.  We  have  to  inquire  what  determines  this 
revivability — what  conditions  they  are  which  render  the 
revivals  more  or  less  distinct.* 

Since  feelings  are  rarely,  or  indeed  never,  revived  singly 
— since  the  things  we  remember  are,  as  the  word  implies, 
put  together  out  of  feelings  standing  in  certain  relations; 
it  results  that  in  the  illustrations  to  be  given  we  shall  have 
to  deal  more  with  clusters  of  revived  feelings  than  with 
individual  revived  feelings.  But  what  is  alleged  of  the  first 
always  holds  of  the  last. 

§  97.  Speaking  generally,  feelings  are  revivable  in  pro- 
portion as  they  are  relational.  The  peripherally-initiated 
feelings  of  external  origin  are  more  representable  than  those 
of  internal  origin;  and  both  of  these  can  be  represented 
with  greater  facility  than  the  centrally-initiated  feelings. 

The  most  highly  relational  feelings  are  the  visual;  and 
these  are  of  all  feelings  the  most  easily  reproduced  in 
thought.  The  redness  of  a  soldier's  coat,  the  blue  of  the 
sky,  the  whiteness  of  the  snow-covered  ground,  can  be 
revived  in  consciousness  at  any  moment  with  scarcely  an 
effort,  and  with  relatively-great  clearness.  The  glare  of  an 
electric  light  may  be  so  vividly  conceived  as  to  produce 
something  like  a  sense  of  dazzling.  Ideal  feel- 

ings of  sound  arise  before  the  mind  with  a  facility  and 
a  strength  almost  as  great.     The  report  of  a  cannon,  the 

*  I  here  use  the  word  revivability  rather  than  the  word  recoverability, 
because  it  has  less  objectionable  implications.  To  recover  anything  in- 
volves a  voluntary  act ;  and  to  call  a  thing  recoverable,  is  to  say  that  it  is 
something  which  can  be  re-obtained  by  a  voluntary  act.  But  a  great 
part  of  our  ideal  feelings  arise  without  volition,  and  often  in  spite  of 
volition.  The  word  revivable  applies  equally  well  to  the  ideal  feelings 
which  are  voluntary  and  those  which  are  involuntary. 


230  THE  INDUCTIONS  OP  PSYCHOLOGY. 

blast  of  a  trumpet,  a  groan,  or  a  hiss,  may  be  imagined 
instantly  and  very  distinctly.  Sensations  of  touch 

and  pressure,  if  less  representable,  are  representable  readily 
and  with  considerable  clearness.  The  softness  and  hardness, 
the  smoothness  and  roughness,  of  different  surfaces, 
have  tolerably  distinct  ideal  forms  that  recur  with 
facility.  The  less  relational  feelings  externally 

initiated — those  of  taste  and  smell — are  neither  so  easily  nor 
so  strongly  reproduced.  A  colour  or  sound  may  be  remem- 
bered in  an  instant;  but  a  specified  flavour  or  odour  is  not 
so  quickly  recalled,  and  the  ideal  feeling  does  not  approach 
in  vividness  so  nearly  to  the  real  feeling. 

We  pass  to  the  peripherally-initiated  feelings  of  internal 
origin.  A  particular  muscular  effort  cannot  be  represented 
as  quickly  or  as  clearly  as  a  particular  sound  or  colour; 
and  though  an  intense  pain  suffered  in  a  limb  may  be  re- 
called with  considerable  distinctness,  it  is  observable  that 
the  ideal  pain  does  not  approach  so  nearly  to  the  real  pain 
as  does  a  remembered  scream  to  the  consciousness  of  an 
actual  scream,  or  as  does  the  thought  of  a  flash  of  lightning 
to  the  perception  of  a  flash  of  lightning.  When  we 

come  to  those  peripherally-initiated  feelings  to  which 
ordinarily  states  of  the  viscera  give  rise,  we  find  the  degree 
of  revivability  very  small.  It  is  difficult  to  call  into  con- 
sciousness the  feeling  of  hunger.  To  think  of  the  circum- 
stances along  with  which  hunger  occurs  is  easy;  but  after  a 
hearty  meal  it  is  next  to  impossible  to  represent  any  degree 
of  that  craving  for  food  which  existed  before  the  meal. 
Similarly  with  thirst. 

Of  the  centrally-initiated  feelings  or  emotions,  the  like  is 
true  in  a  qualified  sense.  As  before  pointed  out,  there 
is  not  between  actual  and  ideal  emotions  the  same  sharp 
division  as  between  actual  and  ideal  feelings  of  other  kinds. 
Emotions  are  excited,  not  by  physical  agencies  themselves 
but  by  certain  complex  relations  among  them.  Hence,  only 
by  representations  of  such  complex  relations  are  ideal 


THE   REVIVABILITY  OF  FEELINGS.  231 

emotions  aroused.  When  so  aroused,  however,  they  may 
rise  to  any  degree  of  vividness,  until  they  become  actual 
emotions.  But  the  fact  which  we  have  here  to  note  as  con- 
forming to  the  principle  enunciated,  is  that  an  emotion 
cannot  be  at  once  revived  in  the  same  way  that  a  feeling  of 
light  or  sound  can.  It  is  impossible  to  bring  instantly  into 
consciousness  the  passion  of  anger,  or  that  of  joy,  in  however 
faint  a  form.  Representation  of  either  can  be  achieved 
only  by  imagining,  and  dwelling  upon,  some  circumstances 
calculated  to  produce  it;  and  this  takes  an  appreciable 
time. 

§  98.  The  revivability  of  past  feelings  varies  inversely  as 
the  vividness  of  present  feelings.  This  antagonism  holds  to 
a  certain  degree  between  past  and  present  feelings  in  gen- 
eral ;  but  it  holds  to  a  much  greater  degree  between  past  and 
present  feelings  belonging  to  the  same  order. 

Take  first  the  general  antagonism.  Every  one  knows 
that  when  a  tremendous  sound  or  an  astounding  spectacle 
absorbs  the  attention,  it  is  next  to  impossible  to  think  of 
anything  else — next  to  impossible  to  entertain  irrelevant 
ideas.  Indeed,  consciousness  sometimes  becomes  so  entirely 
filled  with  the  present  overpowering  impressions  as  to  ex- 
trude our  habitual  ideas:  producing  what  we  call  absence 
of  mind.  Less  extreme  illustrations  are  furnished  by  the 
interruptions  to  currents  of  voluntary  thought  that  result 
from  violent  pains  or  loud  noises.  And  that  the  shutting 
out  of  primary  feelings  facilitates  the  revival  of  secondary 
feelings,  is  also  implied  by  the  common  habit  of  closing  the 
eyes  when  trying  to  imagine  anything  very  clearly. 

The  more  special  antagonisms  are  of  considerable  interest. 
"We  saw  in  a  previous  chapter  that  primary  feelings  of 
any  order,  while  they  have  much  power  of  excluding  from 
consciousness  primary  feelings  of  the  same  order,  have  less 
power  of  excluding  from  consciousness  primary  feelings 
of  other  orders.    Here  we  have  to  note,  what  may  be  re- 


232  THE  INDUCTIONS  OF  PSYCHOLOGY. 

garded  as  a  corollary,  that  primary  feelings  of  any  order  are 
greater  obstacles  to  secondary  feelings  of  that  order  than 
they  are  to  secondary  feelings  of  other  orders.  Visual 
impressions  of  great  distinctness  offer  a  scarcely-appreciable 
resistance  to  the  imagination  of  sounds — say  those  forming 
a  melody.  The  revival  in  thought  of  a  person  recognized 
yesterday,  is  but  little  interfered  with  by  the  flavours  of  the 
things  we  are  eating.  Nor  do  the  sensations  received  from 
objects  held  in  the  hands,  hinder  us  much  from  thinking  of 
things  we  have  seen,  or  listened  to,  or  tasted,  or  smelt.  But 
the  sounds  we  are  hearing  tend  very  decidedly  to  keep  out 
of  consciousness  other  sounds  of  which  we  wish  to  think. 
Visual  sensations  stand  considerably  in  the  way  of  visual 
ideas.  And  there  are  still  more  conspicuous  antagonisms 
between  the  primary  feelings  and  the  secondary  feelings 
of  lower  orders. 

The  different  degrees  of  these  antagonisms  are,  indeed, 
worthy  of  notice;  since  they  admit  of  being  generalized, 
and  are  not  without  significance.  The  law  appears  to  be 
that  among  the  most  relational  feelings,  the  primary  of  any 
order  resist  the  secondary  of  the  same  order  to  the  least 
extent;  and  that  the  resistance  becomes  more  decided  in 
proportion  as  we  descend  to  feelings  that  are  less  and 
less  relational.  Beginning  with  the  most 

relational  feelings,  it  is  observable  that  only  by  a 
very  intense  visual  sensation  are  the  ideas  of  other 
visual  sensations  entirely  excluded.  Thus  it  is  impos- 
sible while  staring  at  the  Sun  to  think  of  green;  but  it  is 
quite  possible,  or  even  easy,  while  looking  at  a  surface 
coloured  red,  to  think  of  a  patch  of  green  covering  part  of 
its  area;  and  we  can,  with  considerable  distinctness,  imagine 
the  clustered  colours  forming  the  remembrance  of  any  object, 
while  the  retina  is  receiving  the  clustered  colours  yielded  by 
actual  objects  quite  different  from  it.  Of  auditory 

impressions  the  like  may  be  said.  Loud  sounds  prevent  us 
from  bringing  the  ideas  of  other  sounds  into  consciousness; 


THE  REVIVABILITY  OF  FEELINGS.  233 

but  they  must  be  extremely  loud  to  do  this.  And  when 
listening  to  an  orchestra,  it  will  be  found  that  while,  during 
the  ybr^  passages,  it  is  difficult  to  imagine  some  other  musi- 
cal combination  than  that  which  is  being  heard,  it  is  com- 
paratively easy  during  the  jncmo  passages.  Much  the 
same  holds  among  feelings  of  touch.  The  sensations  yielded 
by  an  object  held  loosely,  do  not  prevent  us  from  remember- 
ing the  sensations  yielded  by  other  quite  different  objects; 
and  it  is  needful  to  grasp  an  actual  object  very  strongly,  so 
that  the  sensations  of  touch,  or  rather  of  pressure,  verge  into 
those  of  pain,  before  remembered  tactual  feelings  are  quite 
extruded.  When  we  come  to  such  comparatively-unre- 
lational  feelings  as  the  gustatory  and  olfactory,  we  find  this 
antagonism  far  more  marked.  While  tasting  something 
decidedly  bitter,  sweetness  cannot  be  thought  of:  indeed, 
tastes  of  even  moderate  intensity  almost  prevent  us  from 
imagining  other  tastes.  And  this  antagonism  reaches  its 
extreme  among  the  visceral  feelings,  where,  indeed,  it 
appears  to  be  absolute. 

§  99.  Other  things  being  equal,  the  revivability  of  a 
feeling  varies  with  its  strength;  and  other  things  being 
equal,  its  revivability  varies  with  the  number  of  times  it  has 
been  repeated  in  experience.  The  triteness  of  these  truths 
must  not  prevent  us  from  here  briefly  noticing  them. 

The  glow  of  a  gorgeous  sunset  continues  to  be  recallable 
long  after  faintly  coloured  scenes  of  the  same  date  have 
been  forgotten.  The  sound  of  a  trumpet  may  be  more 
quickly  and  clearly  imagined  than  that  of  a  bassoon.  It  is 
easier  to  remember  the  taste  of  something  that  is  intensely 
sour  or  sweet  or  bitter  than  the  taste  of  something  that  Is 
almost  insipid.  And  a  very  severe  pain  leaves  a  trace  in 
memory  which  lasts  long  after  the  traces  left  by  slight 
aches  and  discomforts  have  disappeared. 

How  repetitions  even  of  faint  feelings  produce  great 
revivability  of  them,  we  8§e  on  comparing  our  domestic 


234  THE  INDUCTIONS  OF  PSYCHOLOGT. 

experiences  with,  less  common  experiences.  The  colour  of 
the  paper  in  a  frequented  room,  subdued  though  it  is,  can 
be  very  distinctly  recalled.  The  tone  of  a  voice  which  is 
heard  daily,  may  be  thought  of  much  more  easily  and  truly 
than  the  tone  of  a  voice,  not  more  marked  in  character,  that 
has  been  heard  but  once  or  twice. 

But  the  other  things  which  we  have  -supposed  to  be  equal, 
are  usually  not  equal.  Besides  the  psychological  state 
which,  as  we  have  seen,  influences  the  revivability,  there  is 
the  physiological  state,  which  also  influences  it  in  several 
ways.    These  we  must  now  consider. 

§  100.  The  degree  of  revivability  of  a  feeling  depends  in 
part  on  the  extent  to  which  the  nervous  centre  concerned 
was  capable  of  undergoing  much  molecular  change,  and 
evolving  much  of  the  concomitant  feeling,  when  the  original 
excitation  was  received.  Several  factors  co-operate  to  deter- 
mine its  capability.  A  complete  state  of  repair  is  one  of 
them.  An  active  circulation  is  another.  A  blood  rich  in 
the  materials  required  for  both  disintegration  and  integra- 
tion is  a  third.  The  respective  shares  of  these  factors 
cannot  be  determined;  for  the  three  usually  vary  together. 
But  the  influences  of  two,  at  least,  may  be  pretty  clearly 
identified. 

When  the  attention  has  been  long  occupied  with  any 
class  of  impressions — when,  that  is  to  say,  the  nervous 
centres  concerned  have  been  worn  by  persistent  action, 
the  impressions  received  cannot  be  recalled  as  clearly  as 
those  received  when  these  nervous  centres  were  unworn. 
Excluding  cases  in  which  abnormal  excitement  of  the  local 
circulation  has  been  produced  (cases  to  be  dealt  with  under 
the  next  head),  it  is  a  familiar  fact  that  after  many  hours 
spent  in  listening  to  music,  or  in  looking  at  pictures,  the 
clustered  sensations,  auditory  or  visual,  are  either  not 
revivable  at  all,  or  are  less  distinctly  revivable  than  those 
which  came  first  in  the  concert  or  the  picture  gallery.    If 


THE  REVIVABILITY  OF  FEELINGS.  235 

we  take  longer  periods  of  continued  activity,  broken  though 
they  are  by  short  periods  of  rest,  a  like  fact  meets  us.  The 
experience  of  every  tourist  supplies  an  instance.  His  first 
grand  mountain-views  he  can  call  to  mind  more  clearly  than 
the  equally-grand  views  he  had  after  being  among  the 
mountains  for  a  month. 

That  feelings  excited  when  the  general  circulation  is  very 
vigorous  are  more  revivable  than  usual,  is  a  truth  that  may 
be  variously  exemplified.  Evidence  is  furnished  by  both 
temporary  and  permanent  exaltations  of  the  circula- 
tion. Impressions  of  trivial  things  in  which  no 
particular  interest  was  taken,  often  survive  in  memory  when 
impressions  of  much  more  important  or  imposing  things 
fade  away;  and,  on  considering  the  circumstances,  it  will 
frequently  be  found  that  such  impressions  were  received 
when  the  energies  were  high — when  exercise,  or  pleasure, 
or  both,  had  greatly  raised  the  action  of  the  heart.  That  at 
times  when  strong  emotion  has  excited  the  circulation  to  an 
exceptional  degree,  the  clustered  sensations  yielded  by 
surrounding  objects  are  revivable  with  great  clearness,  often 
throughout  life,  is  a  fact  noticed  by  writers  of  fiction  as  a 
trait  of  human  nature.  As  with  these  quicker 
variations  of  vascular  activity,  so  with  the  slower  variations. 
The  receptivity  of  impressions  is  high  during  those  portions 
of  life  in  which  the  blood  is  propelled  in  full  and  rapid 
currents.  Feelings,  peripheral  or  central,  experienced  in 
youth,  are  long  remembered;  and  while  the  vigour  of 
manhood  continues,  the  sensations  and  emotions  leave 
lasting  traces. 

Equally,  or  more,  obvious  is  the  converse  truth,  that  the 
revivability  of  feelings  excited  during  a  state  of  feebleness 
is  comparatively  small.  The  effects  of  depressed  circula- 
tion, whether  produced  by  disorder  or  by  age,  alike  show 
this.  The  lowered  action  of  the  heart  which 

accompanies  great  nervous  prostration,  has  for  one  of  its 
effects  a  marked  decrease  of  receptivity.    Things  seen  and 


236  THE  INDUCTIONS  OP  PSYCHOLOGY. 

said  and  heard  are  forgotten  very  quickly — often  in  a  few 
days.  Even  the  lowered  vital  activity  which  we  know  as 
great  fatigue,  is  characterized  by  a  diminished  retentiveness 
of  impressions.  When  we  pass  to  that  flagging 

of  the  circulation  which  accompanies  the  decline  of  life, 
abundant  evidence  meets  us.  Gradually  as  the  vigour 
decreases  there  comes  an  increasing  failure  of  memory. 
The  experiences  of  a  month  ago,  or  of  last  week,  or  of 
yesterday,  are  not  revivable;  and  in  the  closing  stages  of 
decay  things  that  were  looked  at  and  sounds  that  were  heard 
but  a  few  minutes  ago,  are  found  to  have  left  no  traces. 

There  is  reason  to  think  that,  independently  of  the  general 
circulation,  exaltations  and  depressions  of  the  cerebral  circu- 
lation, whether  normally  or  abnormally  produced,  also  affect 
the  degree  of  revivability  of  the  feelings  experienced. 

§101.  All  the  circumstances  under  which  an  excitation 
originally  occurred  being  supposed  the  same,  the  degree  of 
revivability  of  the  feeling  that  was  produced,  varies  with  the 
physiological  conditions  that  exist  when  the  revival  takes 
place  or  is  attempted.  Other  things  equal,  a  given  past 
feeling  may  be  brought  into  consciousness  vividly,  faintly, 
or  not  at  all,  according  as  the  nervous  centre  concerned  is  or 
is  not  well  repaired  and  well  supplied  with  blood  at  the 
moment  the  remembrance  is  suggested.  The  evidence 
assignable  in  proof  of  this  proposition  is  mostly  entangled 
with  that  assigned  in  proof  of  the  last;  but  a  sufficiency  of 
it  may  be  disentangled. 

In  that  state  of  high  spirits  which  results  from  good 
nutrition  and  raised  circulation,  it  is  observable  that  the 
memories  are  more  distinct  than  usual.  Ideas  rise  up  in 
abundance  without  effort.  Similarly,  the  vascular  excite- 
ment caused  by  emotion,  providing  it  does  not  reach  that 
extreme  pitch  at  which  it  prostrates  the  heart,  causes  a 
rush  of  unusually  vivid  ideas — ideas  so  vivid  that  they  are 
sometimes,  as  under  great  fear,  mistaken  for  realities. 


THE  REVIVABILITY  OF  FEELINGS.  237 

How  decreased  revivability  of  feelings  originally  strong, 
goes  along  with  enfeebled  circulation,  is  exemplified  in 
those  exhausted  by  long  illnesses.  Highly  nervous  sub- 
jects, too,  in  whom  the  action  of  the  heart  is  greatly  lowered, 
habitually  complain  of  loss  of  memory  and  inability  to  think 
— symptoms  which  diminish  as  fast  as  the  natural  rate  of 
circulation  is  regained.  It  is,  however,  in  old  age 

that  the  relation  between  failureof  circulation  and  decreased 
revivability  of  feelings  which  were  efficiently  impressed,  is 
most  familiar.  The  power  to  recall  experiences  received 
during  adult  and  declining  life,  when  the  vital  energies  were 
flagging,  is  the  first  to  disappear;  and  pre3ently  experiences 
received  during  early  life,  when  the  vital  energies  were  high, 
cease  to  be  distinctly  revivable. 

It  may  be  well  to  add  that  variations  of  local  circulation, 
as  well  as  of  general  circulation,  affect  the  ability  to  revive 
feelings.  The  illusions  of  delirium  exemplify  the  extreme 
vividness  to  which  revived  feelings  may  rise  when  the  cere- 
bral circulation  is  excessive;  and  the  loss  of  consciousness 
caused  by  cerebral  anaemia  exemplifies  the  converse  result. 

§  102.  Of  course  quality  as  well  as  quantity  of  blood  is 
a  factor,  modifying  alike  the  strength  with  which  an  im- 
pression is  retained  and  the  facility  with  which  it  can  be 
recalled.  The  influence  of  this  factor  has  doubtless  a  share 
in  producing  some  of  the  effects  above  ascribed  to  variations 
of  circulation ;  for  quality  of  blood  generally  rises  and  falls 
along  with  the  vigour  of  its  propulsion.  Abnormal  devia- 
tions, however,  show  us  that  quality  has  its  separate  effects. 

When  the  circulation  has  been  artificially  exalted  by 
stimulants,  there  is  an  easy  and  rapid  current  of  thoughts, 
showing  itself  in  what  we  describe  as  unusual  brilliancy. 
And  when  the  exaltation  is  produced  by  certain  drugs,  as 
opium  and  hashish,  the  revived  impressions  of  things  seen 
and  heard,  approach  in  vividness  to  the  original  impressions. 

"We  have  another  class  of  examples  in  insane  people. 


238  THE  INDUCTIONS  OF  PSYCHOLOGY. 

That  in  them  there  has  arisen  some  abnormal  quality  of 
blood,  is  now  a  generally-received  opinion;  and  to  this  ab- 
normal quality  is  ascribed  that  undue  vividness  of  the 
representative  feelings  which  causes  a  confusion  of  them 
with  presentative  feelings. 

These  extreme  cases  warrant  us  in  supposing  that  there 
are  minor  variations  in  the  revivability  of  feelings,  accom- 
panying those  minor  variations  in  the  quality  of  the  blood 
which  are  caused  by  differences  in  the  activities  of  the 
viscera  and  differences  in  the  supplies  of  food  and  oxygen. 

§  103.  The  correspondence  of  these  several  a  posteriori 
conclusions  with  the  a  ^>/^*6>W  conclusions  derivable  from  the 
data  of  Psychology,  must  be  noticed. 

The  fact  that  feelings  of  any  order  tend  to  exclude  ideas 
of  the  same  order  more  than  they  do  ideas  of  other  orders, 
is  to  be  expected  if  particular  bundles  of  nerve-fibres 
and  groups  of  nerve-vesicles  are  the  agents  of  particular 
orders  of  feelings;  for,  manifestly,  when  the  structures  con- 
cerned are  undergoing  those  molecular  changes  which  have 
vivid  feelings  for  their  correlatives,  other  molecular  changes, 
which  have  faint  feeling  for  their  correlatives,  must  be 
greatly  obscured.  Moreover,  we  may  see  why  this  exclusion 
is  more  stringent  among  the  unrelational  orders  of  feelings 
than  among  the  relational  orders  of  feelings ;  since,  in  pro- 
portion as  an  order  of  feelings  is  relational,  it  must  have  a 
complex  nervous  centre,  and  in  proportion  as  a  nervous 
centre  becomes  complex,  it  becomes  easy  for  one  part  of  it 
to  be  occupied  in  one  way  while  another  part  of  it  is  occupied 
in  another  way. 

That  strong  environing  actions  generate  feelings  which 
are  more  distinctly  revivable  than  those  generated  by  weak 
environing  actions,  is  also  a  fact  inferable  from  physiological 
premises.  For  as  strong  environing  actions  produce  strong 
nervous  discharges  and  great  amounts  of  those  central 
molecular  changes  of  which  feelings  are  the  correlatives,  it 


THE  KEVIVABILITY  OF  FEELINGS.  239 

ie  obvious  that  they  must  produce  in  high  degrees  those 
structural  changes,  whatever  they  may  be,  to  which  the 
revivability  of  the  feelings  is  due. 

Similarly,  it  follows  that  those  exaltations  of  vital  activity 
which  facilitate  such  structural  changes,  and  aid  the  rapid 
nutrition  which  perpetually  prepares  the  parts  for  them, 
must  conduce  to  the  revivability  of  the  feelings  experienced; 
while  depression  of  the  energies  must  do  the  reverse. 


CHAPTER  VI. 

THE    EEVIVABILTTY    OF    RELATIONS    BETWEEN    FEELNGS. 

§  104.  Much  that  was  said  in  the  last  chapter  in  illustra- 
tion of  the  propositions  it  sets  forth,  serves  to  illustrate  the 
parallel  propositions  to  be  set  forth  in  this  chapter.  Mind 
being  composed  of  feelings  and  relations  between  feelings, 
and  every  mental  act  involving  both  kinds  of  components,  it 
happens  that,  in  exemplifying  the  revivability  of  feelings  as 
modified  by  various  conditions,  there  has  been  exemplified 
also  the  revivability  of  relations  between  feelings. 

Nevertheless,  there  remain  to  be  enunciated  truths  which 
in  the  last  chapter  were  but  tacitly  implied,  and  other  truths 
that  were  not  even  remotely  indicated.  For  though  revival 
of  a  feeling  involves  revival  of  the  relations  in  which  it  was 
originally  experienced;  and  though  revival  of  a  cluster  of 
feelings,  constituting  an  ordinary  idea,  involves  revival  of  a 
whole  plexus  of  relations  in  which  the  feelings  stood  to  one 
another;  there  is  not  involved  in  the  recognition  of  these 
facts,  the  further  fact  that  relations  may  be  in  great  measure 
parted  from  the  related  feelings  and  revived  by  themselves. 
Since  quite  different  pairs  of  impressions  may  stand  to 
one  another  in  the  same  relation  of  co-existence ;  and  since 
a  sequence  may  hold  together  impressions  now  of  this  order 
and  now  of  that;  and  since  differences  the  same  in  degree 
may  be  presented  here  by  impressions  of  one  species  and 

here  by  impressions  of  another;   it  results  that  relations  of 

240 


THE  REVIVABILITY  OF  RELATIONS.  241 

Co-existence,  of  Sequence,  and  of  Difference,  come  to  be 
separable  from  particular  pairs  of  impressions,  and  acquire 
a  quasi-mde^endence.  Their  independence  never  becomes 
complete;  for  a  relation  cannot  be  conceived  without  two 
related  terms.  But  being  common  to  terms  of  all  orders, 
they  come  to  be  conceived  apart  from  terms  of  any  particular 
order — can  have  their  terms  changed  in  consciousness  with- 
out being  themselves  changed;  and  thus  gain  a  kind  of 
revivability  so  far  independent  of  any  particular  terms,  as 
to  have  an  illusive  appearance  of  being  independent  of  all 
terms. 

What  we  have  here  to  do,  then,  is  to  consider  the  reviva- 
bility of  relations  as  dissociated  little  or  much  from  related 
feelings.  Though  the  several  forms  of  thought  under  which 
our  feelings  are  presented  and  re-presented  cannot  exist 
without  some  contents,  yet  their  contents  may  be  in  great 
part  extruded;  and  we  have  to  observe  how  these  com- 
paratively empty  forms  comport  themselves  in  respect  of 
their  revivabilities,  as  influenced  by  psychological  and 
physiological  conditions. 

§  105.  Relations  in  general  are  more  revivable  than  feel- 
ings in  general.  Whether  it  be  a  compound  relation  of  Co- 
existence, or  a  compound  relation  of  Sequence,  or  a  com- 
pound relation  of  Difference,  we  shall  find  that  the  rela- 
tion is  more  distinctly  representable,  and  more  enduring  in 
memory,  than  are  its  terms. 

^Naturally,  this  truth  is  the  least  conspicuous  among  the 
most  relational  feelings,  since  these  being  highly  revivable, 
there  is  a  comparatively  small  margin  for  difference  between 
their  revivability  and  that  of  the  relations  between  them. 
Still  the  difference  may  even  here  be  perceived.  If  we 
recall  a  room  frequented  in  childhood,  the  relative  posi- 
tions of  the  door,  the  windows,  the  fireplace,  arise  in 
consciousness  instantly:  we  may  or  may  not  think  of 
some  of  the  colours,  but  if  we  do,  it  is  by  a  subsequent 


242  THE  INDUCTIONS  OF  PSYCHOLOGY. 

act.  Similarly  with  the  tactually-disclosed  co- 

existent impressions  which  we  remember  as  a  knife-handle. 
The  combination  of  these  constituting  the  conception  of  its 
shape,  recurs  more  readily  in  thought  than  does  the  par- 
ticular intensity  of  any  one  of  the  pressures,  or  than  does 
the  particular  feeling  of  coldness. 

"With  relations  of  sequence  as  exhibited  among  the  audi- 
tory feelings,  this  contrast  is  more  decided.  To  begin  an 
air  in  the  right  key,  most  persons  find  very  difficult:  with- 
out the  help  of  an  instrument,  the  first  note  is  often  wrong 
by  a  third  or  even  a  fifth.  But  the  duration  of  the  first 
note  is  more  nearly  remembered.  Though  the  time  at  which 
the  air  is  taken  may  differ  somewhat  from  the  time  as 
originally  heard,  it  does  not  differ  so  much  as  the  pitch. 
It  is  further  observable,  as  showing  the  same  thing,  that 
while  the  rhythm  of  a  melody  may  be  repeated  in  thought 
with  great  exactness,  we  cannot  delight  ourselves  by  recall- 
ing with  the  same  exactness  the  rich  timbre  of  the  tones  in 
which  we  heard  the  melody  rendered. 

When  we  descend  to  the  least  relational  feelings,  the 
greater  revivability  of  relations  than  of  their  terms  becomes 
very  manifest.  We  remember  for  a  long  time  with  accu- 
racy the  spot  in  which  an  acute  pain  was  felt,  though  the 
pain  itself  is  not  representable  with  anything  like  its  origi- 
nal acuteness ;  and  if  the  pain  was  a  throbbing  one,  we  can 
recall  its  intervals  with  approximate  correctness.  So, 

too,  is  it  with  the  central  feelings.  The  succession  of  cer- 
tain strong  emotions  passed  through  yesterday,  is  easier  to 
recall  than  the  emotions  themselves.  It  is  the  same  with 
the  relation  of  each  emotion  to  its  antecedents.  The  cir- 
cumstances under  which  we  were  angry  may  be  reproduced 
in  consciousness  instantly;  but  the  anger  itself  cannot  be 
reproduced  instantly. 

It  is  worth  considering  whether  the  possibility  of  ex- 
tended and  complex  thinking  does  not  in  part  depend  on 
this  greater  revivability  of  relations  than  of  their  terms. 


THE  REVIVABILITY  OF  RELATIONS.  243 

We  habitually  pass  in  thought  from  concept  to  concept, 
briefly  recognizing  the  essentials  of  each — the  essential 
relations  of  its  elements  to  one  another  and  to  other  things. 
If  the  feelings  between  which  all  these  relations  exist 
arose  in  consciousness  with  as  much  promptness  and  vivid- 
ness, consciousness  would  be  so  encumbered  with  materiala 
that  involved  processes  of  reasoning  would  be  greatly  im- 
peded, if  not  prevented. 

§  106.  As  different  orders  of  feelings  are  more  or  less 
relational,  so,  too,  in  a  sense,  different  orders  of  relations  are 
more  or  less  relational.  For  just  as  some  kinds  of  feelings 
are  more  capable  of  entering  into  relations  with  one  another 
than  other  kinds  are,  so  some  kinds  of  relations  are  more 
capable  of  entering  into  relations  with  one  another  than 
other  kinds  are.  Understanding  the  expression  in  this 
sense,  we  may  say  that  the  most  relational  of  relations  are 
those  of  Co-existence.  Co-existences  may  be  trebly  com- 
pounded, and  are,  indeed,  trebly  compounded  in  most  acts 
of  thought:  impressions  are  presented  and  represented  in 
those  triple  relations  of  position  involved  in  the  conception 
of  place.  Sequences  are  much  less  relational ;  for  they  can 
enter  into  relation  with  one  another  not  in  three  directions 
at  once,  but  only  in  one  direction.  Successive  intervals  of 
time  stand  related  to  one  another  as  greater,  or  less,  or 
equal ;  and  in  the  beats  and  bars  of  music,  these  relations  of 
equality  and  difference  in  portions  of  time  are  themselves 
compounded  into  other  relations — relations,  however,  which 
are  essentially  serial.  The  least  relational  of  relations  are 
the  primary  onea — those  of  Difference;  for  though  these 
enter  into  relations  with  one  another  whenever  we  contem- 
plate two  differences  as  equal,  or  more  or  less  unequal,  in  de- 
gree, yet  (unless  it  be  in  the  higher  divisions  of  Mathematics) 
they  do  not  enter  into  relations  more  compound  than  these. 

This  description  of  the  several  classes  of  relations  as 
more  or  less  relational,  is  introductory  to  the  fact  here  to 
17 


244  THE  INDUCTIONS  OF  PSYCHOLOGY. 

be  set  down,  that  just  as  the  most  relational  of  feelings 
are  the  most  revivable,  so,  too,  are  the  most  relational  of 
relations  the  most  revivable.  Relations  of  Co-existence, 
whether  we  take  any  particular  plexus  of  them  consti- 
tuting the  perception  of  a  form,  or  whether  we  take  the 
aggregate  of  them  constituting  the  consciousness  of  Space, 
have  a  revivabilitj  far  exceeding  that  of  all  other  relations. 
We  think  of  distances,  of  directions,  of  sizes,  of  shapes,  of 
arrangements  among  objects,  with  little  or  no  effort  and 
with  great  clearness;  and  these  variously-compounded 
relations  we  conceive  as  frameworks  which  we  can  imagine 
to  be  occupied  by  other  objects,  or  to  be  unoccupied. 
The  revivability  of  relations  of  Co-existence  is,  indeed,  so 
extreme  that  they  cannot  be  wholly  suppressed — an  assem- 
blage of  them  greater  or  less  in  extent,  partly  occupied 
and  partly  unoccupied,  forms  an  inextinguishable  element 
of  consciousness. 

Relations  of  Sequence,  less  relational  than  those  of  Co- 
existence, are  less  revivable.  Though  it  is  true  that,  as 
organized  into  the  abstract  conception  of  Time,  relations  of 
Sequence  can  no  more  be  wholly  excluded  from  conscious- 
ness than  those  of  Co-existence,  yet,  as  thus  abstracted,  they 
do  not  form  so  dominant  an  element  of  consciousness:  the 
integrated  aggregate  of  space-relations  habitually  present  in 
thought,  is  much  larger  and  much  clearer  than  the  integ- 
rated aggregate  of  time-relations.  It  is  observable,  too, 
that  particular  space-relations  are  more  clearly  and  correctly 
representable  than  particular  time-relations.  We  can  mark 
out  with  greater  accuracy  the  length  of  an  inch  or  of  a  foot, 
than  we  can  assign  the  length  of  an  interval  as  being  one 
minute  or  as  being  ten  minutes. 

Simple  relations  of  Difference  (those  between  feelings) 
are  neither  so  readily  nor  so  accurately  revivable  as  relations 
of  Difference  between  co-existences  or  between  sequences, 
nor  as  the  relations  of  Co-existence  and  Sequence  them- 
selves.    We  can  better  remember  the  proportion  between 


THE  REVIVABILITY  OP  RELATIONS.  245 

two  lengths  wHcli  we  observed  simultaneously,  and  can 
more  truly  reproduce  in  thought  the  ratio  between  the 
rhythms  of  movements  in  a  machine,  than  we  can  recall  the 
degree  of  contrast  between  two  lights  we  saw  or  two  weights 
we  lifted;  and  where  the  differences  are  between  the  unre- 
lational  feelings,  as  tastes,  and  smells,  and  visceral  sensa- 
tions, we  can  recall  them  but  vaguely. 

§  107.  As  presented  feelings  hinder  the  representation  of 
other  feelings,  so  do  presented  relations  hinder  the  represent- 
ation of  other  relations;  but  they  do  this  in  a  smaller  de- 
gree. It  is  with  relations,  too,  as  with  feelings,  that  the 
antagonism  of  the  presented  to  the  represented  is  more  mani- 
fest between  those  of  the  same  order  than  between  those  of 
different  orders.  Omitting  superfluous  illustrations,  we  will 
note  a  few  distinctive  traits  only. 

Among  the  most  relational  relations,  as  among  the  most 
relational  feelings,  the  present  impedes  remembrance  of  the 
past  in  the  smallest  degree;  and  among  these,  too,  we  find 
presented  relations  interfering  in  the  smallest  degree  with 
the  representation  of  relations  of  the  same  order.  Visual 
relations,  no  matter  how  vividly  impressed,  never  absolutely 
exclude  from  consciousness  other  visual  relations  of  which 
we  choose  to  think.  We  saw  that  a  very  intense  visual  feel- 
ing temporarily  prevents  us  from  calling  to  mind  another 
visual  feeling;  biit  though  it  is  impossible  to  gaze  at  the  sun 
and  think  of  green,  it  is  quite  possible  to  gaze  at  the  sun 
and  think  of  a  square.  Similarly,  a  trial  will  show  that  if 
while  contemplating  any  scene  we  think  of  some  other  scene, 
we  recall  the  distribution  of  its  parts  more  readily  than  we 
recall  its  colours. 

Relations  of  Sequence,  much  less  relational  as  they  are, 
show  us  a  greater  interference  of  the  present  with  remem- 
brance of  the  past.  Though  while  looking  at  one  shape 
we  can  easily  think  of  another  quite  unlike  it,  we  cannot, 
without  difficulty,  if  at  all,  call  to  mind  a  rhythmical  com- 


246  THE  INDUCTIONS  OF  PSYCHOLOGY. 

bination  of  intervals  wholly  different  from  another  to  which 
we  are  listening — cannot  bring  into  consciousness  the  move- 
ment of  a  melody  in  |-time  while  listening  to  a  melody  in 
common  time.  When  the  rhythm  we  hear  is  very  simple, 
as  the  splash  of  oars  while  rowing,  it  is,  indeed,  possible  to 
think  of  some  complex  rhythm  disagreeing  with  it  entirely ; 
but  only  the  disciplined  musician  can  attend  at  once  to  ideal 
and  real  rhythms  that  are  both  complex  and  quite  unlike  one 
another. 

It  is  obvious  that  presented  relations  of  Difference  be- 
tween simple  feelings,  stand  very  much  more  in  the  way  of 
represented  relations  of  Difference  between  simple  feelings 
— especially  where  the  differences  are  between  feelings  of 
the  same  order. 

§  108.  A  kindred  truth  to  be  here  noticed  (the  counter- 
part to  which  should  have  been  noticed  when  dealing  with 
the  revivability  of  feelings)  is  that  the  representation  of 
any  relations  is  hindered  by  the  presence  in  consciousness 
of  other  represented  relations ;  and  that  the  hindrance,  while 
either  great  or  insuperable  if  the  two  sets  of  relations 
are  of  the  same  order,  is  comparatively  small  if  they  are  of 
different  orders. 

The  most  relational  of  relations  may  be  superposed  in 
thought,  one  set  upon  another:  we  can  imagine  the  out- 
lines of  a  face,  and  then,  without  losing  consciousness  of 
it,  may  imagine  a  geometrical  figure  described  over  the 
game  visual  area.  We  cannot,  however,  deal  similarly  with 
unlike  sets  of  sequences.  The  rhythm  of  some  tune  which 
has  taken  possession  of  us,  and  of  which  we  vainly  try  to 
rid  ourselves  by  thinking  of  other  things,  may  be  effectually 
expelled  by  rehearsing  in  thought  another  tune. 

But  when  the  relations  are  of  different  orders,  their  re- 
presentations have  but  little  power  of  mutual  exclusion. 
We  see  this  in  the  case  just  referred  to;  for  the  tune  that 
pesters  us  keeps  running  on  through  consciousness  while 


THE  REVIVABILITY  OF  RELATIONS.  247 

we  are  thinking  of  places,  or  actions,  or  matters  of  business. 
Hence,  too,  results  the  frequent  failure  of  the  receipt  for 
obtaining  sleep  when  excited — that  of  counting;  for  after 
a  short  time  the  counting  becomes  almost  automatic,  and 
is  carried  on  while  consciousness  is  still  chiefly  occupied  by 
the  exciting  thoughts. 

§  109.  From  the  mental  conditions  that  affect  the  re- 
vivability  of  relations,  we  pass  now  to  the  physical  condi- 
tions that  affect  their  revivability.  As  might  be  expected, 
those  which  hold  with  feelings  hold  also  with  the  relations 
between  feelings.  It  is  needless  to  trace  out  their  influ- 
ences as  fully  as  before.  A  single  illustration  of  each  will 
suffice. 

Proof  that  relations  established  in  consciousness  at  a 
time  when  the  nervous  centres  are  worn  by  long-continued 
action,  have  a  comparatively  small  revivability,  is  furnished 
by  the  familiar  experience  that  knowledge  acquired  by 
"  cramming  "  is  soon  lost.  That  relations  im- 

pressed when  the  circulation  is  vigorous  are  more  re- 
vivable  than  those  impressed  when  the  circulation  is 
feeble,  we  see  in  the  decaying  receptivity  of  age.  Dur- 
ing youth  and  early  manhood,  it  is  easy  to  recall  the 
various  events  on  each  of  the  successive  days  recently 
passed,  and  there  is  never  any  doubt  what  is  the  day 
of  the  month;  but  as  life  advances  and  the  heart's 
action  flags,  these  relations  of  recent  times  and  actions 
quickly  fade.  Similarly,  relations  impressed  when 

the  circulation  was  strong  and  that  were  once  easily  recall- 
able, become  difficult  to  recall  when  the  circulation  has  been 
rendered  abnormally  feeble.  Thus,  it  is  a  common  symptom 
with  nervous  subjects  to  make  mistakes  in  spelling  quite 
simple  words;  and  in  states  of  extreme  prostration  such 
persons,  as  well  as  those  greatly  reduced  by  illness,  forget 
where  they  are,  and  even  who  they  are. 

Quality,  as  well  as  quantity,  of  blood  has  an  influence. 


248  THE  INDUCTIONS  OF  PSYCHOLOGY. 

A  fact  before  referred  to  as  illustrating  the  relativity 
of  relations,  may  here  be  again  named  as  illustrating 
the  variations  of  their  revivability  thus  caused — the  fact, 
namely,  that  opium  produces  intensified  and  exaggerated 
representations  of  spaces  and  times. 

§  110.  On  comparing  these  subjective  truths  with  the  ob- 
jective truths  presented  by  the  nervous  system,  we  may  trace, 
as  in  other  cases,  a  general  congruity. 

That  relations  of  any  order,  presented  or  represented, 
greatly  hinder,  or  wholly  prevent,  the  representation  of  rela- 
tions of  the  same  order,  but  hinder  much  less,  or  scarcely  at 
all,  the  representation  of  relations  of  other  orders,  might  be 
inferred  from  the  data  with  which  we  set  out.  If,  through 
a  plexus  of  nerve-fibres,  there  is  propagated  the  particular 
set  of  nervous  discharges  which  answer  physically  to  what 
is  psychically  a  certain  set  of  perceived  or  conceived  rela- 
tions, an  obstacle  is  thereby  put  to  the  simultaneous  propa- 
gation through  them  of  a  different  set  of  nervous  discharges 
answering  to  a  different  set  of  conceived  relations.  But  a 
separate  plexus  of  nerve-fibres,  the  discharges  through 
which  answer  to  relations  of  another  order,  may  be  simul- 
taneously excited  without  producing  the  same  confusion, 
and  may  yield  to  consciousness  its  partially-independent 
train  of  ideas — partially-independent  we  must  say,  because 
the  actions  of  the  two  plexuses  having  to  be  co-ordinated  at 
some  common  centre  (for  otherwise  the  corresponding  ideas 
would  not  belong  to  one  consciousness)  there  must  always 
result  some  interference. 

That  the  revivability  of  relations  varies  with  the  state  of 
repair  of  the  nervous  centres  and  the  supply  of  blood  to 
them,  is  also  a  fact  harmonizing  with  physiological  infer- 
ence. For  be  it  high  repair,  or  much  blood,  or  special  qual- 
ity of  blood,  it  is  clear  that  whatever  conduces  to  a  powerful 
nervous  discharge  through  any  plexus  of  nerve-fibres,  the 
physical  changes  in  which  answer  to  the  psychical  changes 


THE  REVIVABILITY  OF  RELATIONS.  249 

known  as  certain  relations,  must  cause  a  corresponding 
vividness  of  the  relations — must  alike  give  great  clearness 
to  the  consciousness  of  the  more  familiar  relations  of  the 
cluster,  and  bring  into  consciousness  those  remoter  and  less 
frequently-repeated  relations  of  the  cluster  which,  with 
feebler  nervous  discharges,  would  not  come  into  conscious- 
ness at  all. 


CHAPTER  Vn. 

THE    ASSOCIABILITY    OF    FEELINGS. 

§  111.  In  preceding  chapters,  a  good  deal  has  been  said 
by  implication  about  the  phenomena  usually  treated  under 
the  head  of  Association.  When  tracing  out  the  composi- 
tion of  Mind,  we  saw  that  feelings  cohere  in  unlike  degrees 
in  different  tracts  of  consciousness;  and  what  were  there 
described  as  cohesions  may  be  otherwise  described  as  asso- 
ciations. More  recently,  too,  in  the  chapter  on  the  Reviva- 
bility  of  Feelings,  much  was  tacitly  asserted  respecting  the 
Associability  of  Feelings;  since,  other  things  equal,  reviva- 
bility  varies  as  associability. 

The  truths  thus  observed  from  points  of  view  already 
passed,  we  must  nevertheless  here  briefly  glance  at  afresh 
from  a  more  advanced  point  of  view,  before  we  go  on  to 
consider  certain  further  truths  covered  by  the  title  of  this 
chapter. 

§  112.  We  divided  feelings  into  the  central,  commonly 
called  emotions,  and  the  peripheral,  commonly  called  sensa- 
tions; which  last  we  re-divided  into  those  internally 
initiated,  which  we  may  conveniently  call  ento-peripheral, 
and  those  externally  initiated,  or  epi-peripheral.  Of  these 
three  great  groups  of  feelings  the  first  are  extremely  unre- 
lational ;  the  second  are  somewhat  more  relational ;  and  the 

third  are  relational  in  a  comparatively  high  degree.     Be* 

250 


THE  ASSOCIABILITY  OF  FEELINGS.  251 

ginning  with  the  central  or  least  relational  feelings,  which 
have  no  limitations  in  space  and  are  but  vaguely  bounded 
in  time,  we  found  that,  passing  through  the  ento-peri- 
pheral  to  the  epi-peripheral,  we  come  to  feelings  more  and 
more  definitely  limited  by  one  another  in  space,  or  time,  or 
both:  the  sharpest  limitations  being  among  the  feelings 
that  are  epi-peripheral  in  the  highest  degree.  And  along 
with  this  increasing  definiteness  of  mutual  limitation  we  saw 
that  there  goes  an  increasing  tendency  to  mutual  cohesion. 

This,  then,  represents  the  order  of  associability  of  the 
feelings.  The  relational  are  the  mutually-limited,  which  are 
the  mutually-coherent,  which  are  the  associable.  Feelings 
of  the  central  or  of  the  ento-peripheral  kinds  which  have 
been  experienced  together  or  in  succession,  either  do  not 
recall  one  another  into  consciousness  at  all  or  do  it  but 
feebly  after  many  repetitions;  while  feelings  of  the  epi-peri- 
pheral kind  which  occur  together  or  in  succession  but  a  few 
times,  become  linked  in  such  a  way  that  the  vivid  or  the 
faint  form  of  one  arouses  the  faint  forms  of  the  rest.*  In- 
deed among  the  auditory  and  visual  feelings,  single  presenta- 
tions in  serial  or  simultaneous  groups  cause  such  connexions, 
that  one  member  of  a  group  being  afterwards  presented  or 
represented,  representations  of  the  other  members  follow 
it,  often  with  few  or  no  omissions. 

Manifestly,  associability  and  revivability  go  together; 
since,  on  the  one  hand,  we  know  feelings  to  be  associable  only 
by  the  proved  ability  of  one  to  revive  another,  and  since,  on 
the  other  hand,  the  revival  of  any  feeling  is  effected  only 
through  the  intermediation  of  some  feeling  or  feelings 

*  Though  a  vivid  or  faint  antecedent  feeling  usually  brings  into  con- 
sciousness as  its  consequent  only  a  faint  feeling,  yet  it  is  not  true,  as  com- 
monly supposed,  that  the  consequent  is  never  a  vivid  feeling.  Ideas  do, 
in  some  cases,  arouse  sensations.  Several  instances  occur  in  my  own 
experience.  I  cannot  think  of  seeing  a  slate  rubbed  with  a  dry  sponge 
without  there  running  through  me  the  same  cold  thrill  that  actually  see- 
ing  it  produces. 


252  THE  INDUCTIONS  OF  PSYCHOLOGY. 

with  which  it  is  associated.  Hence  the  conditions  that 
favour  revivability  are  those  which  favour  associability. 
These,  both  psychological  and  physiological,  having  been 
enumerated  in  the  last  chapter,  may  be  passed  over. 

§  113.  There  remains  to  be  here  considered  the  ultimate 
law  to  which  the  association  of  feelings  conforms.  Leaving 
out  all  the  variable  concomitants  of  any  simple  association, 
there  are  two  constant  elements  directly  presented  by  it — 
the  feelings  and  the  relations  between  them;  and  two  con- 
stant elements  indirectly  implied  by  it — previously-experi- 
enced similar  feelings  and  previously-experienced  similar 
relations.  Hence,  respecting  the  structure  of  the  entire 
cluster,  there  arises  the  question — Which  are  the  primary 
or  original  connexions  and  which  are  the  secondary  or  deriva- 
tive connexions?    For,  to  use  a  symbolic  illustration,  it  may 

a  h 
happen  that  in  the  coherent  cluster   i  i   the  elements  a,  J, 

c-d 

apparently  held  together  by  some  bond,  are  not  themselves 
connected  at  all,  but  are  kept  in  juxtaposition  by  the  links 
which  hold  them  respectively  to  the  coupled  elements  c-d. 
Let  us  state  the  matter  more  specifically. 

The  consciousness  of  two  feelings  presented  together,  or 
one  just  after  the  other,  implies,  first,  the  consciousness  of 
each  feeling  as  such  or  such — implies  recognition  of  it  as 
like,  in  some  or  all  of  its  characters,  to  a  feeling  previously 
experienced.  Even  where  one  of  the  two  feelings  (say  the 
taste  of  a  new  wine  or  of  a  new  drug)  is  unexperienced,  it 
is  still  assimilated  to  some  genus  of  feelings — is  known  as 
sweet,  or  bitter,  or  sour.  The  consciousness  further  in- 
cludes two  relations  between  the  feelings — their  relation  of 
difference,  and  their  relation  of  co-existence  or  of  sequence ; 
and  the  knowing  each  of  these  relations  as  such  or  such 
implies  past  like  relations  to  which  it  is  assimilated.  Now 
the  question  to  be  asked  is,  whether  the  association  estab- 
lished between  the  two  feelings  results  immediately  from 
the  cohesion  of  the  one  to  the  other,  or  results  mediately 


THE  ASSOCIABILITY  OF  FEELINGS.  253 

from  the  cohesion  of  each  feeling  and  each  relation  be- 
tween them,  to  their  respective  similars  in  experience. 
The  usual  supposition  is  that  the  cohesion  is  immediate; 
but  we  shall  find  good  reason  for  concluding  that  it  is 
mediate.  The  inquiry  is  divisible  into  two  inquiries — how 
the  feelings,  past  and  present,  comport  themselves  towards 
one  another,  and  how  their  relations,  past  and  present, 
comport  themselves  towards  one  another.  These  must  be 
dealt  with  apart,  though  some  inconvenience  attends  the 
separation  of  them;  for  neither  can  be  fully  answered  with- 
out both  being  answered.  Such  large  gaps  as  the  instructed 
reader  perceives  in  this  chapter  on  the  Associability  of  Feel- 
ings, he  will  find  filled  up  in  the  next  chapter  on  the  Associ- 
ability of  the  Relations  between  Feelings. 

This  premised,  let  us  consider  in  what  way  feelings,  real 
and  ideal,  behave  when  separated,  so  far  as  may  be,  from 
particular  relations. 

§  114.  Members  of  the  three  great  groups  of  feelings 
severally  associate  themselves  primarily  with  members  of 
their  own  group.  Of  the  central  feelings,  or  emotions,  this 
proposition  is  less  manifestly  true  than  of  the  rest,  for  the 
sufficient  reason  that  they  are  the  least  relational  of  feel- 
ings: cohering  but  little  with  feelings  of  any  kinds,  the 
differences  in  their  cohesive  tendencies  are  the  least  de- 
cided. Still,  it  is  observable  that  a  central  feeling  when 
it  arises,  is  known  as  belonging  to  the  class  we  call  emo- 
tions, and  not  to  the  class  we  call  sensations.  Peripheral 
feelings  being  all  localized,  vaguely  if  not  definitely,  these 
central  feelings,  not  being  localized,  are  in  this  respect 
antithetical  to  them;  and  each,  in  the  act  of  recognition, 
aggregates  with  the  class  of  unlocalizable  feelings,  instead 
of  with  the  class  of  localizable  feelings.  It  is  true  that  in 
consequence  of  the  disturbances  of  certain  viscera  which 
powerful  emotions  produce,  the  ento-peripheral  feelings 
thence  resulting,  are,  in  common  speech,  partially  confounded 


254  THE  INDUCTIONS  OP  PSYCHOLOGY. 

with  the  central  feelings;  but  though  the  sensation  due  to 
disturbed  action  of  the  heart  is  often  metaphorically  iden- 
tified with  the  emotion  causing  the  disturbance,  yet  every 
one  really  distinguishes  between  the  consequence  and  the 
cause,  and  classes  the  cause  apart.  When  we 

pass  to  the  ento-peripheral  feelings  it  is  at  once  obvious 
that  each,  in  the  instant  of  presentation,  is  known  as 
initiated  within  the  body.  Be  it  one  of  the  least  localizable 
of  these  feelings,  such  as  hunger,  or  be  it  a  more  localizable 
one,  such  as  a  pain  in  the  bowels,  or  be  it  one  localizable 
with  comparative  definiteness,  as  an  ache  in  the  finger,  it  is, 
as  having  a  place  more  or  less  bounded  within  the  bodily 
framework,  at  once  separated  in  consciousness  from  the 
central  feelings  on  the  one  hand  and  from  the  epi-peripheral 
feelings  on  the  other.  The  only  cases  where  this  associa- 
tion is  indefinite,  are  cases  where  the  feeling  is  initiated 
near  the  division  between  the  two  kinds  of  peripheral  feel- 
ings; as  when  an  itching  just  below  the  surface  is  con- 
founded with  a  tickling  upon  the  surface,  or  as  where  the 
sensation  of  heat  due  to  sub-cutaneous  congestion  is  undis- 
tinguished from  the  sensation  of  heat  due  to  adjacent  hot 
matter.  The  epi-peripheral  feelings  show  us  this 

instant  integration  of  each  with  its  class,  even  more  con- 
spicuously. The  sensation  produced  by  a  blow,  by  some- 
thing grasped,  by  an  odour,  by  a  flash,  or  by  a  sonorous 
vibration,  cannot  arise  in  consciousness  without  being 
grouped  with  the  general  assemblage  of  sensations  initiated 
at  the  surface  and  ascribed  to  objective  actions.  The  asso- 
ciation is  not  a  matter  into  which  thought  or  will  enters: 
it  is  instantaneous  and  absolute. 

A  further  fact  of  kindred  meaning  may  now  be  noted. 
Each  feeling  as  it  arises  associates  itself  instantly  not  with 
its  class  only,  but  also  with  its  sub-class.  The  central 
feelings  are  but  indefinitely  divisible  into  sub-classes;  and 
hence  among  them  there  is  but  little  manifestation  of  this 
truth.    We  may  pass  over  them.  The  ento-peri' 


THE  ASSOCIABILITY  OF  FEELINGS.  255 

pheral  feelings  illustrate  this  sub-classification  and  cohesion 
quite  clearly.  On  thrusting  itself  into  consciousness,  one 
of  these,  while  known  as  originating  within  the  body,  is  at 
the  same  time  known  as  a  craving,  or  as  a  pain,  or  as  a  mus- 
cular strain:  it  falls  into  its  secondary  group  while  falling 
into  its  primary  group.  Similarly  with  the  epi- 

peripheral  feelings.  A  colour  the  moment  it  is  perceived, 
not  only  irresistibly  aggregates  with  the  class  of  feelings 
that  originate  on  the  outer  surface  and  imply  outer  stimuli, 
but  also  with  the  sub-class  of  visual  sensations,  and  cannot 
be  forced  into  any  other  sub-class.  While  being  recog- 
nized, a  sound  falls  simultaneously  into  the  general  assem- 
blage of  feelings  derived  from  the  senses  which  hold 
converse  with  the  external  world,  and  also  into  the  more 
special  assemblage  of  feelings  distinguished  as  auditory; 
and  no  effort  will  separate  it  from  this  special  assemblage. 
And  to  say  that  a  smell  cannot  be  thought  of  as  a  colour 
or  a  sound,  is  to  say  that  it  associates  itself  indissolubly 
with  previously-experienced  smells. 

A  sub-sub-classification  of  like  nature  is  no  less  in- 
stantaneous. This  is  traceable  to  a  considerable  extent 
among  the  feelings  excited  within  the  body:  hunger  is  at 
once  known  as  hunger  and  not  as  thirst;  an  acute  pain 
coheres  in  thought  with  acute  pains,  and  not  with  what  we 
distinguish  as  aches.  But  it  is  among  the  feelings  yielded 
by  the  special-sense  organs  that  the  sub-sub-classing  is 
most  conspicuous.  When  we  look  at  the  sky,  we  think  of 
its  colour  as  a  feeling  of  external  origin,  as  belonging  to 
the  sub-division  of  externally-originated  feelings  called 
visual,  and  also  as  belonging  to  the  group  of  these  called 
blues:  it  does  not  suggest  reds  or  yellows,  and  refuses  to 
unite  with  them  in  consciousness.  A  mouse's  squeak  as- 
similates itself  in  thought  with  sounds  of  high  pitch,  and 
not  with  sounds  like  the  bellowing  of  a  bull.  The  taste  of 
honey  aggregates  with  sweet  tastes  in  general,  of  which  it  is 
one — not  with  such  tastes  as  those  of  quinine,  or  of  castor  oil. 


256  THE  INDUCTIONS  OF  PSYCHOLOGY. 

There  is  a  still  greater  speciality  of  these  associations; 
as  where  bright  colours  of  each  kind  connect  themselves 
in  thought  with  bright  colours  of  the  same  kind  and  not 
with  dull  ones,  or  as  where  loud  sounds  of  any  pitch  sug- 
gest other  loud  sounds  of  that  pitch  and  not  faint  ones. 
But  without  further  instances  the  reader  will  see  that  the 
law  holds  down  to  the  minutest  sub-divisions  of  kind  and 
quality. 

§  115.  What  is  the  most  general  statement  of  these 
facts?  It  is  that  be  there  or  be  there  not  any  other  kind 
of  association,  the  primary  and  essential  association  is  be- 
tween each  feeling  and  the  class,  order,  genus,  species,  and 
variety,  of  preceding  feelings  like  itself. 

This  association  is  automatic — is  not  an  act  of  thought 
that  may  or  may  not  take  place,  but  constitutes  the  very 
recognition  of  each  feeling.  A  feeling  cannot  form  an 
element  of  Mind  at  all,  save  on  condition  of  being  associated 
with  predecessors  more  or  less  the  same  in  nature.  In  the 
process  of  this  automatic  association  each  feeling  coheres 
instantly  with  the  great  group  to  which  it  belongs;  in- 
stantly, too,  with  its  sub-group  within  this;  and,  among  the 
relational  feelings,  goes  practically  at  the  same  time  into 
its  sub-sub-group.  The  automatic  character  of  the  process 
is  qualified  only  when  we  come  to  the  smallest  groups, 
its  association  with  one  or  other  of  which  may  occupy  an 
appreciable  interval.  Thus,  the  sensation  of  red  passes  in  a 
moment  to  its  class  as  epi-peripheral,  in  the  same  moment 
to  its  order  as  visual,  and  with  equal  rapidity  to  the 
genus  of  colours  distinguished  as  reds;  but  it  falls  into 
the  species  known  as  scarlet  or  that  known  as  crimson  less 
promptly,  and  it  is  a  matter  of  deliberation  and  uncertainty 
whether  we  think  of  it  as  like  the  scarlet  of  a  soldier's  coat 
or  like  that  of  a  poppy — like  the  crimson  of  a  peony  or  like 
that  of  a  carnation. 

Now  this  cohering  of  each  feeling  with  previously-ex- 


THE  ASSOCIABILITY  OP  FEELINGS.  257 

perienced  feelings  of  the  same  class,  order,  genus,  species, 
and,  so  far  as  may  be,  the  same  variety,  is  the  sole  process 
of  association  of  feelings.  All  other  phenomena  of  associa- 
tion of  feelings  are  consequent  on  the  union  of  this  process 
with  a  parallel  and  simultaneous  process  to  be  described  in 
the  next  chapter. 

§  116.  Before  passing  to  this  next  chapter,  let  us  briefly 
note  the  congruity  between  these  facts  disclosed  by  intro- 
spection and  the  facts  disclosed  by  outward  observation, 
which  were  set  down  among  our  data. 

The  associability  of  feelings  with  those  of  their  own 
kind,  group  within  group,  corresponds  to  the  general  ar- 
rangement of  nervous  structures  into  great  divisions  and  sub- 
divisions. The  central  feelings  arise  within  the  great  cere- 
bral masses;  and  the  subjective  connexion  shown  in  the 
instant  association  of  each  with  its  class,  answers  to  the 
objective  connexion  between  one  set  of  nervous  actions 
occurring  in  these  great  masses  and  other  sets  of  nervous 
actions  that  have  occurred  in  the  same  masses.  The  peri- 
pheral feelings,  again,  initiated  by  disturbances  upon  or  with- 
in the  body,  have  their  seat  in  the  subjacent  nervous  mass  (or 
masses,  but  probably  iYiQinedulla  oblongata  is  the  sole  sensa- 
tional centre) ;  and  the  classing  of  one  of  these  feelings  with 
sensations  in  general,  instead  of  with  emotions,  answers  to 
the  connexion  between  one  nervous  change  in  this  subjacent 
mass  and  other  nervous  changes  in  it.  Simi- 

larly with  the  leading  sub-classes.  The  particular  parts  of 
that  developed  end  of  the  spinal  cord  in  which  peripheral 
feelings  of  unlike  kinds  are  localized,  remain  at  present  un- 
determined. But  if  we  remember  that  great  sub-classes  of 
the  peripheral  feelings,  as  the  visual,  have  great  bundles  of 
nerve-fibres  which  carry  the  disturbances  arousing  them 
from  surface  to  centre,  and  that  other  such  great  sub- 
classes, as  the  auditory,  have  other  such  bundles,  we  may 
be  sure  that  each  sub-class  of  peripheral  feelings  has  its 


358  THE  INDUCTIONS  OF  PSYCHOLOGY. 

own  sub-division  of  central  vesicular  structure.  And  if  so, 
the  instant  automatic  aggregation  of  each  peripheral  feeling 
with  those  of  its  own  order,  answers  psychically  to  the  local- 
ization of  the  nervous  excitement  causing  it,  within  that  sub- 
division of  vesicular  structure  which  is  the  seat  of  other  feel- 
ings of  its  order.  That  the  like  holds  of  still  smaller  groups 
of  feelings  and  clusters  of  vesicles,  is  an  obvious  inference. 
What  is  the  implication?  If  the  association  of  each  feel- 
ing with  its  general  class,  answers  to  the  localization  of  the 
corresponding  nervous  action  within  the  great  nervous  mass 
in  which  all  feelings  of  that  class  arise — if  the  association  of 
this  feeling  with  its  sub-class,  answers  to  the  localization  of 
the  nervous  action  within  that  part  of  this  great  nervous 
mass  in  which  feelings  of  this  sub-class  arise,  and  so  on  to 
the  end  with  the  smallest  groups  of  feelings  and  smallest 
clusters  of  nerve- vesicles;  then,  to  what  answers  the  asso- 
ciation of  each  feeling  with  predecessors  identical  in  kind? 
It  answers  to  the  re-excitation  of  the  particular  vesicle  or 
vesicles  which,  when  before  excited,  yielded  the  like  feeling 
before  experienced.  The  appropriate  stimulus  having  set 
up  in  certain  vesicles  the  molecular  changes  which  they 
undergo  when  disturbed,  there  is  aroused  a  feeling  of  the 
same  quality  with  feelings  previously  aroused  when  such 
stimuli  set  up  such  changes  in  these  vesicles.  And  the 
association  of  the  feeling  with  preceding  like  feelings,  corre- 
sponds to  the  physical  re-excitation  of  the  same  structures. 
Whence  we  see  clearly  that  the  ultimate  law  of  association 
of  feelings,  as  above  described,  has  a  definite  physical  coun- 
terpart; and  that  there  is  no  room  for  any  other  law  of 
association  of  feelings. 


CHAPTEE  Yin. 

THE   ASSOCIABILITY   OF    RELATIONS    BETWEEN    FEELINGS. 

§  117.  The  associability  of  relations,  like  the  associability 
of  feelings,  has  been  to  some  extent  implicitly  dealt  with 
under  preceding  heads.  When  considering  the  composition 
of  Mind,  we  saw  that  relations  as  well  as  feelings  cohere 
with  one  another  in  consciousness;  and  what  was  there  de- 
scribed as  cohesion  of  relations  is  otherwise  describable  as 
association  of  relations.  Again,  in  the  last  chapter  but  one, 
different  classes  of  relations  were  observed  to  be  revivable 
in  different  degrees,  which  implies  that,  other  things  equal, 
they  are  associable  in  different  degrees.  Moreover,  we  saw 
how  the  revivability  of  relations  varies  in  degree  according 
to  the  fulfilment  of  sundry  conditions,  psychical  and  physi- 
cal; whence  it  follows  that  their  associability  similarly 
varies. 

Though  these  truths  need  not  be  again  contemplated  in 
detail  from  our  present  point  of  view,  there  are  one  or  two 
leading  aspects  of  them  which  we  must  glance  at  before 
passing  on  to  the  general  law  remaining  to  be  set  forth. 

§  118.  That  the  most  relational  of  relations  are  the  most 

associable  is  a  truism;  for  the  relations  which  enter  into 

relation  with  one  another  most  easily  are  the  relations  most 

easily  associable  with  one  another. 

Th$  most  relational  of  relations  are,  as  we  before  saw, 
18  269 


260  THE  INDUCTIONS  OF  PSYCHOLOGY. 

those  of  Co-existence  as  visually  presented;  and  these  are 
associable  with  extreme  facility.  We  sleep  in  a  strange  bed- 
room, and  getting  up  in  the  dark  to  reach  the  water-bottle, 
recall  at  once  the  position  of  the  washing-stand.  We  read 
a  book,  and  without  having  specially  observed  the  fact, 
remember  that  a  passage  we  want  to  find  lies  near  the  bot- 
tom of  a  left-hand  page.  So  quickly  do  these  relations  of 
co-existent  positions  connect  with  one  another,  that  those 
of  many  things  seen  at  the  same  instant  can  be  simulta- 
neously reproduced  in  thought. 

Relations  of  Sequence  are  associable  into  simple  com- 
binations with  considerable  facility,  though  with  less  facility. 
Two  or  three  successive  motions  made  by  a  person  we  are 
watching  are  readily  remembered,  though  we  fail  to  re- 
member the  order  of  many  such  motions.  After  hearing 
the  first  bar  or  the  first  phrase  of  a  new  melody,  it  is  easy 
forthwith  to  repeat  the  rhythm  in  thought;  but  the  series 
of  rhythms  which  the  entire  melody  presents,  do  not  (in 
most  minds  at  least)  recur  correctly  without  repetitions 
more  or  less  numerous.  This  smaller  associability  is,  how- 
ever, chiefly  shown  in  the  contrast  between  our  ability  to 
recall  many  co-existences  presented  together,  and  our  in- 
ability to  recall  many  sequences  presented  together.  We 
look  into  a  room  and  instantly  connect  in  consciousness  the 
relative  positions  of  two  or  three  persons,  the  table,  the  sofa, 
&c.,  so  that  we  can  afterwards  describe  how  they  stood; 
but  we  cannot  in  the  same  way  take  in  at  a  glance,  and  re- 
produce in  thought,  the  several  combined  movements  of  a 
horse  in  trotting:  we  can  clearly  think  of  the  alternate 
swings  of  the  fore-legs  by  themselves  or  of  the  hind-legs 
by  themselves;  but,  unless  after  specially  observing  it,  we 
cannot  remember  which  hind-leg  comes  to  the  ground  after 
the  near  fore-leg. 

There  is  considerable  associability  of  co-existences  with 
sequences — those  sequences,  at  least,  in  which  the  co-exist- 
ing positions  composing  Space  are  traversed  in  successive 


THE  ASSOCIABILITY  OP  RELATIONS.  261 

instants  of  Time.  This  association  of  relations,  underlying 
as  we  shall  hereafter  see  our  conceptions  of  Space  and  Time, 
leads  by  perpetual  repetition  to  indissoluble  connexions  in 
consciousness,  which  govern  our  thoughts  absolutely.  It  will 
be  instructive  here  to  observe  how  multitudinous  expe- 
riences have  so  fused  together  certain  of  these  relations, 
that  one  being  presented  brings  up  the  consciousness  of 
the  other  spite  of  every  effort  to  exclude  it.  Let  us  take 
an  instance.  We  move  about  day  by  day  on  foot 

and  in  vehicles,  perpetually  passing  objects,  some  of 
them  also  moving,  but  most  of  them  stationary. 
In  all  these  cases  there  is  relative  motion,  which,  as 
visually  perceived,  is,  other  things  equal,  the  same 
whether  it  results  from  the  motion  of  the  subject  while 
the  object  is  stationary,  or  whether  it  results  from  the 
motion  of  the  object  while  the  subject  is  stationary. 
Ordinarily  we  can  distinguish  between  these  two  causes 
of  relative  motion.  The  relative  motion  of  stationary  ob- 
jects is  always  accompanied  by  the  consciousness  of  either 
our  own  locomotive  activity  or  the  activity  of  something 
carrying  us — the  action  of  the  horse,  or  the  jolting  of  the 
carriage,  or  both.  Conversely,  when  relative  motion  is  seen 
while  we  are  stationary,  we  habitually  see  along  with  it  those 
vital  or  mechanical  actions  which  cause  locomotion.  Hence 
the  relative  motion  of  adjacent  objects  which  do  not  exhibit 
any  of  the  direct  or  indirect  concomitants  of  locomotion, 
comes  to  be  strongly  associated  in  thought  with  our  own 
motion;  and,  unless  other  perceptions  furnish  evidence  to 
the  contrary,  the  perception  of  relative  motion  under  such 
conditions  causes  an  irresistible  consciousness  of  our  own 
motion,  even  when  we  are  motionless.  This  is  remarkably 
illustrated  when  sitting  in  a  train  at  a  railway  station  with 
another  train  standing  along-side  in  such  way  as  to  exclude 
the  view  of  all  other  objects  (so  shutting  out  contradictory 
evidence).  When  one  of  the  two  trains  starts,  the  relative 
motion  which  we  perceive  on  looking  at  the  other  train  is  just 


262  THE  INDUCTIONS  OF  PSYCHOLOGY. 

as  likely  to  be  due  to  the  starting  of  the  other  train  as  to  the 
starting  of  our  own.  But  the  tendency  always  is  to  think 
that  our  own  train  is  moving.  Continually  we  find  our- 
selves wrong;  but  the  knowledge  of  the  fact  that  under 
these  conditions  the  sense  of  our  own  motion  is  often  illu- 
sive, does  not  enable  us  to  exclude  it.  The  association  of 
these  relations  has  become  automatic,  and  the  resulting 
organic  inference,  taking  possession  of  consciousness,  re- 
tains it  until  some  decisive  contradictory  impression  sud- 
denly, with  a  shock,  dispels  it. 

§  119.  Before  seeking  the  ultimate  law  of  associa- 
tion of  relations,  let  us  observe  how  relations,  like  feel- 
ings, aggregate  with  their  respective  classes  and  sub- 
classes. 

When  we  see  two  things,  or  two  parts  of  a  thing,  simul- 
taneously, the  relation  between  them  automatically  classes 
itself  with  relations  of  Co-existence  in  general.  We  cannot 
prevent  it  from  cohering  with  that  great  division  of  rela- 
tions the  terms  of  which  do  not  differ  in  their  order  of  pre- 
sentation— space-relations.  So,  too,  when  watch- 
ing the  motion  of  a  body  from  one  place  to  another,  when 
listening  to  successive  words,  or  when  perceiving  light  after 
striking  a  match,  the  relation  between  the  states  of  con- 
sciousness produced,  instantly  and  irresistibly  associates  itself 
with  Sequences.  To  be  conscious  of  the  relation  at  all,  is 
to  be  conscious  of  it  as  belonging  to  that  great  division  of 
relations  the  terms  of  which  differ  in  their  order  of  pre- 
sentation. It  automatically  classes  itself  with  time-rela- 
tions. Equally,  the  observation  of  a  difference  be- 
tween two  impressions,  whether  simultaneous  or  successive, 
implies  its  assimilation  to  Differences  in  general.  While  in 
the  order  of  its  terms  the  relation  can  be  known  at  all  only 
as  a  relation  of  co-existence  or  sequence,  its  terms  can  be 
known  at  all  as  standing  in  relation,  only  by  distinguishing 
between  them  in  consciousness;  and  the  act  of  distinguish- 


THE  ASSOCIABILITY  OF  RELATIONS.  263 

ing  between  them  is  the  act  of  classing  their  relation  along 
with  relations  of  Difference. 

At  the  same  time  each  relation  passes  into  one  or  other 
of  certain  sub-classes.  A  co-existence  between  visual  feel- 
ings, unites  itself  rigidly  with  that  marvellous  aggregate 
of  relations  constituting  our  consciousness  of  visually-per- 
ceived space.  But  when  two  impressions  are  simultaneously 
received  from  things  touched  in  the  dark,  the  relation 
between  them,  while  it  coheres  with  the  general  class  of 
co-existences,  coheres  with  the  sub-class  of  tactually-per- 
ceived  co-existences — a  sub-class  constituting  a  compara- 
tively rudimentary  consciousness  of  space,  which,  though  it 
arouses  an  ideal-consciousness  of  visually-known  space, 
differs  wholly  in  quality  from  this.  And  the  thing  to  be 
noted  is,  that  a  tactually-perceived  relation  of  co-existence 
is  never  confounded  with  a  visually-perceived  one;  but  is 
only,  by  a  comparatively  deliberate  act  of  thought,  remem- 
bered to  have  the  same  objective  equivalent.  Re- 
lations of  Sequence  associate  themselves  into  the  sub-classes 
of  internal  and  external.  This  classification  of  them  neces- 
sarily accompanies  the  classification  of  their  terms.  The 
sequences  between  internal  feelings  and  those  between  ex- 
ternal feelings,  are,  in  the  act  of  knowing  the  feelings  as 
inwardly  or  outwardly  initiated,  distinguished  as  sequences 
belonging  to  the  Ego  or  sequences  belonging  to  the  Non- 
ego;  and  no  member  of  either  group  is  transferable  to  the 
other.  The  instantaneous  sub-grouping  of  relations 
of  Difference  scarcely  needs  pointing  out.  We  observe  two 
heights  or  two  breadths  to  be  unlike,  and  in  thinking  them 
unlike  think  of  their  difference  as  a  difference  in  space- 
occupancy — cannot  think  of  it  as  a  difference  between  times 
or  intensities.  In  being  conscious  of  two  notes  in  music 
as  standing  to  one  another  in  the  ratio  of  minim  and 
crotchet,  the  unlikeness  between  their  lengths  is  cognizable 
only  as  an  unlikeness  between  portions  of  time.  And  simi- 
larly, the  contrast  in  strength  between  two  colours  or  two 


264  THE  INDUCTIONS  OF  PSYCHOLOaY. 

tastes,  passes  in  the  moment  of  perception  into  the  sub- 
class of  contrasts  in  intensity — refuses  to  be  thought  of  as 
a  contrast  in  dimension  or  duration. 

Among  space-relations  may  be  observed  a  further  stage 
of  this  process.  Though  they  have  no  sub-sub-classes 
divided  as  definitely  as  are  the  sub-sub-classes  of  certain 
feelings,  especially  the  epi-peripheral ;  yet  they  are  habi- 
tually thought  of  as  belonging  to  vaguely-distinguished 
assemblages  which  have  reference  to  the  arrangements  of 
the  limbs  and  senses.  In  the  moment  of  perception  a 
visual  relation  of  co-existence  falls  into  that  aggregate  of 
such  relations  composing  the  consciousness  of  the  space 
before  us — cannot  be  associated  with  the  aggregate  of  such 
relations  composing  the  vaguely-conceived  space  behind  us. 
In  like  manner  the  relation  at  once  coheres  with  the  still 
more  special  group  of  relations  constituting  the  space  we 
distinguish  as  above,  or  the  space  we  distinguish  as  below; 
and  it  is  at  the  same  time  automatically  classed  with  space- 
relations  to  the  right  or  to  the  left.  Only  when  it  is  very 
near  to  the  ideal  boundaries  we  make  between  these  regions 
of  space,  may  there  be  an  association  of  it  with  some  other 
than  its  own  group. 

We  are  now  in  a  position  to  appreciate  the  significance 
of  the  ultimate  segregations.  On  looking,  say  at  a  flower 
by  the  roadside,  the  relations  among  the  feelings  of  colour 
which  we  receive  from  its  petals,  instantly  associate  them- 
selves with  relations  of  Co-existence  in  general,  with  the 
sub-class  of  visually-perceived  relations  of  co-existence,  with 
the  sub-sub-class  of  these  relations  forming  the  space  in 
front  of  us,  and  with  the  still  smaller  group  of  these  rela- 
tions aggregated  into  our  conception  of  the  space  low  down 
to  the  right.  But  they  do  more  than  this.  With  equal,  or 
with  almost  equal,  rapidity,  (I  say  almost  equal  because  this 
minor  classification  varies  in  rapidity  with  the  goodness  of 
the  vision)  these  relations  of  co-existent  positions  presented 
by  the  petals  of  the  flower,  associate  themselves  in  con- 


THE  ASSOCIABILITY  OF  RELATIONS.  265 

sciousness  with  tlie  relations  of  co-existent  positions  consti- 
tuting tlie  space  immediately  about  the  flower — the  parti- 
cular portion  of  space  that  is  not  only  the  same  in  direction 
but  the  same  in  distance.  For,  on  observing  what  happens 
when  the  axes  of  the  two  eyes  are  converged  on  an  object,  it 
will  be  perceived  that  we  become  conscious  of  the  space  it 
occupies,  and  of  the  closely-environing  space,  with  much 
more  distinctness  than  we  are  conscious  of  any  other  space. 
Under  such  conditions  we  are  scarcely  at  all  conscious  of 
the  space  behind  us;  we  are  scarcely  at  all  conscious  of  the 
space  far  beyond  the  object,  if  opaque  matter  shuts  out  im- 
pressions from  things  contained  in  it;  we  are  conscious  in 
but  a  vague  way  of  the  space  far  to  the  right  or  to  the  left, 
much  above  or  below;  we  are  conscious  with  some  clearness 
of  the  space  between  our  eyes  and  the  object,  so  far  as  this 
consciousness  is  involved  in  the  conception  of  distance ;  but 
we  have  what  may  be  called  a  detailed  consciousness  of  the 
space  in  and  around  the  object.  It  needs  only  to  look  now 
at  a  thing  quite  near  and  now  at  a  thing  further  off,  now  at 
one  on  this  hand  and  now  at  one  on  the  other,  to  perceive 
that  the  respective  portions  of  space  in  which  they  exist, 
severally  become  indistinct  in  consciousness  as  we  turn  our 
eyes  away;  and  that  distinctness  in  our  consciousness  of 
each  portion  of  space,  results  only  when  the  eyes  yield  a 
distinct  image  of  something  placed  in  it.  That  is  to  say,  any 
co-existing  positions  visually  presented  are  immediately  asso- 
ciated in  thought  with  the  cluster  of  co-existing  positions 
similarly  related  to  us — each  perceived  position  standing  in 
a  relation  of  co-existence  with  self,  associates  itself  most 
closely  with  other  positions  standing  in  like  relations  of  co- 
existence with  self.  And  in  being  classed  with  these  rela- 
tions which  it  is  most  like,  it  arouses  a  consciousness  of 
them;  just  as  a  colour  in  being  recognized  as  red  of  a  parti- 
cular shade,  brings  into  consciousness  ideas  of  other  reds  of 
the  same,  or  nearly  the  same,  shade.  Moreover,  as  we  before 
saw  that  while  a  particular  feeling  of  redness  associates  itself 


366  THE  INDUCTIONS  OP  PSYCHOLOGY. 

irresistibly  and  in  a  moment  with  the  great  class  of  epi- 
peripheral  feelings,  with  the  sub-class  of  visual  feelings, 
with  the  sub-sub-class  of  reds,  but  less  quickly  with  its 
particular  variety  of  reds  ;  so  here  we  may  see  that  while 
this  relation  of  co-existent  positions  associates  itself  in- 
stantly and  rigidly  with  relations  of  co-existent  positions  in 
general,  with  visual  relations  of  co-existent  positions,  with 
the  relations  of  co-existent  positions  constituting  the 
region  of  space  low  down  to  the  right,  it  associates  itself 
less  promptly  with  the  relations  of  co-existent  positions 
that  are  almost  identical:  there  is  some  uncertainty 
in  the  estimation  of  the  distance — an  uncertainty 
which  is  considerable  in  a  person  with  but  one  eye, 
who  continually  finds  himself  wrong,  and  has  to  modify  his 
estimate,  or  to  re-class  the  relation.  This  general 

law  may  be  similarly  traced  among  time-relations.  Suppose 
I  recall  an  event  that  occurred  yesterday;  as,  for  instance, 
the  unexpected  arrival  of  a  friend.  It  is  observable,  in  the 
first  place,  that  all  those  associated  and  consolidated  rela- 
tions of  sequence  which  constitute  the  conception  of  the 
time  before  yesterday,  do  not  (unless  by  some  secondary  act) 
enter  into  consciousness  at  all.  It  is  observable,  in  the  second 
place,  that  the  united  relations  of  sequence  which  form  a  con- 
ception of  the  time  between  now  and  yesterday,  are  not  dis- 
tinctly represented,  but  are  represented  only  in  such  general 
way  as  to  yield  a  measure  of  the  distance  back  at  which  the 
event  occurred.  While  it  is  observable,  in  the  third  place, 
that  the  portion  of  time  to  which  retrospective  consciousness 
is  directed,  becomes  comparatively  distinct  in  detail.  On 
remembering  the  first  sight  of  my  friend's  face  yesterday,  I 
think  not  only  of  his  smile  of  recognition,  of  my  quick  step 
towards  him,  of  our  shaking  hands,  of  the  words  that 
followed,  but  I  also  think  of  the  immediately-preceding 
occurrences — of  my  entrance  into  the  room,  of  my  seeing 
the  back  of  some  person  looking  at  a  picture,  of  his  turning 
round  on  hearing  me,  of  my  surprise  on  seeing  who  it 


THE  ASSOCIABILITY  OF  RELATIONa  267 

was.  I  find,  too,  that  the  moments  immediately  adjacent  to 
any  one  of  these  remembered  actions,  become  more  distinct 
in  consciousness  than  those  at  some  distance  on  either  side 
of  it.  If  I  recall  my  entrance  into  the  room,  the  positions 
in  time  which  made  up  the  interval  before  my  friend 
turned  round,  represent  themselves  quite  clearly — far  more 
clearly  than  those  preceding  his  knock  at  the  door  or 
those  succeeding  our  salutation.  To  make  these  portions  of 
time  equally  clear,  I  must  adjust  my  retrospective  glance  to 
positions  adjacent  to  them.  Thus  it  is  with  Time  as  with 
Space,  that  each  place  in  it  associates  itself  with  places  at 
the  same  distance  from  the  place  we  at  present  occupy;  and 
as  we  turn  our  attention  now  to  one  part  of  the  past  and  now 
to  another,  the  relations  of  sequent  positions  which  consti- 
tute our  consciousness  of  that  part  become  clear,  while  all 
others  lapse  into  vagueness. 

§  120.  Every  relation  then,  like  every  feeling,  on  being 
presented  to  consciousness,  associates  itself  with  like  pre- 
decessors. Knowing  a  relation,  as  well  as  knowing  a  feeling, 
is  the  assimilation  of  it  to  its  past  kindred ;  and  knowing  it 
completely  is  the  assimilation  of  it  to  past  kindred  exactly 
like  it.  But  since  within  each  great  class  the  relations  pass 
one  into  another  insensibly,  there  is  always,  in  consequence 
of  the  imperfection  of  our  perceptions,  a  certain  range  with- 
in which  the  classing  is  doubtful — a  certain  cluster  of  rela- 
tions nearly  like  the  one  perceived,  which  become  nascent 
in  consciousness  in  the  act  of  assimilation.  Along  with  the 
perceived  position  in  Space  or  Time  the  contiguous  positions 
arise  in  consciousness. 

Hence  results  the  so-called  Law  of  Association  by  Con- 
tiguity. When  we  analyze  it.  Contiguity  resolves  itself  into 
likeness  of  relation  in  Time  or  in  Space  or  in  both.  Let 
us  observe  how  in  the  association  of  like  relations  there  is 
involved  the  association  of  contiguous  feelings. 

On  the  one  hand,  relations  of  difference  and  the  time-rela- 


268  THE  INDUCTIONS  OF  PSYCHOLOGY. 

tions  implied  in  the  cognition  of  successive  differences,  are 
elements  without  which  there  can  be  no  consciousness.  On 
the  other  hand,  there  can  be  no  consciousness  of  these  rela- 
tions without  consciousness  of  some  feelings  which  simul- 
taneously yield  them.  We  can  think  of  space-relations,  all 
but  absolutely  empty,  but  we  cannot  think  of  anything 
approaching  to  empty  time-relations.  Time  having  but  one 
dimension,  and  the  measure  of  that  dimension  being  the 
series  of  contained  feelings,  it  follows  that  unless  occupied 
by  some  feelings,  real  or  ideal.  Time  has  no  dimension.  If 
the  objects  around  are  perfectly  stationary  and  silent,  we 
have  still  the  rhythm  of  our  functions  and  the  current  of  our 
thoughts  to  yield  us  marks  by  which  to  measure  duration. 
Necessarily,  then,  when  we  think  of  any  position  in  past 
time,  we  cannot  associate  it  with  its  cluster  of  almost  equi- 
distant positions  in  time,  without  being  conscious  more  or 
less  clearly  of  the  feelings  which  occupied  those  almost  equi- 
distant or  contiguous  positions.  Association  of  feelings 
contiguous  in  time,  is  involved  by  association  of  their  like 
time-relations.  Passing  to  contiguous  co-existent 

feelings,  we  may  see  that  the  association  of  them  results 
from  a  further  complication  of  the  same  process.  Feelings 
known  in  sequence,  and  serving  as  marks  that  measure 
duration,  may  be  sounds  or  odours  which  do  not  necessarily 
connote  Space  at  all  in  a  rudimentary  consciousness.  But 
in  a  consciousness  containing  tactual  and  visual  experiences, 
there  always,  along  with  the  sequent  feelings  caused  by 
inner  or  outer  changes,  occur  certain  feelings,  received  by 
touch  or  sight  or  both,  which  continue  to  co-exist  while 
the  sequent  feelings  are  passing.  These  simultaneously- 
experienced  feelings  yielded  by  things  contiguous  in  space, 
which  persist  side  by  side  in  consciousness  over  an  appreci' 
able  period  measured  by  sequent  feelings,  are  necessarily 
associated  with  these  in  their  time-relations.  Hence  on  re- 
calling any  relations  of  sequence,  there  are  apt  to  recur  the 
various  relations  of  co-existence  which  were  perceived  along 


THE  ASSOCIABILITT  OF  RELATIONS.  269 

with  them.  And  the  feelings  that  occupied  these  nearly 
equi-distant  positions  in  space  that  were  presented  in  these 
nearly  equi-distant  positions  in  time,  being  among  the  feel- 
ings which  made  marks  in  consciousness  at  that  time,  the 
representation  of  that  time  entails  a  recurrence  of  these 
marks. 

The  process  thus  described  as  taking  place  with  simple 
relations  having  simple  feelings  for  their  terms,-  equally 
holds  in  a  plexus  of  relations  among  many  feelings;  as  in 
the  perception  of  an  ordinary  object.  When,  for  instance, 
in  recognizing  a  face  we  saw  last  week,  we  associate  each 
of  the  many  combined  relations  of  position  constituting  its 
form,  with  the  respective  like  relations  before  experienced; 
and  when  along  with  the  recognition  there  arises  the  con- 
sciousness of  a  redness  on  the  cheek  that  was  before  present 
but  is  now  absent;  this  recollection  of  the  colour  that 
occupied  a  particular  place,  results  simply  because  it  was 
one  of  the  elements  entangled  in  the  plexus  of  relations 
which  gave  the  consciousness  its  individuality.  On  before 
seeing  the  face,  this  colour  was  a  term  to  various  rela- 
tions of  difference  involved  in  the  consciousness;  it  was 
presented  at  the  same  instant  of  time  with  the  many  other 
related  feelings  which  the  consciousness  contained;  and  as 
having  a  position  fixed  in  reference  to  all  parts  of  the  face, 
it  entered  into  a  great  number  of  relations  of  co-exist- 
ence. Hence,  having  served  as  a  common  term  to  many 
different  but  combined  relations,  it  happens  that  when  these 
are  again  presented,  the  assimilation  of  them  to  the  like 
relations  before  seen,  entails  a  consciousness  of  the  missing 
term  of  these  like  relations  before  seen.  The  colour  is 
thought  of  in  thinking  of  the  relations;  and  the  difference 
between  the  face  as  remembered  and  the  face  as  perceived 
becomes  manifest. 

Thus,  the  fundamental  law  of  association  of  relations,  like 
the  fundamental  law  of  association  of  feelings,  is  that  each, 
at  the  moment  of  presentation,  aggregates  with  its  like  in 


270  THE  INDUCTIONS  OF  PSYCHOLOGY. 

past  experience.  The  act  of  recognition  and  the  act  of 
association  are  two  aspects  of  the  same  act.  And  the  im- 
plication is  that  besides  this  law  of  association  there  is  no 
other;  but  that  all  further  phenomena  of  association  are 
incidental. 

§  121.  The  congruity  between  this  conclusion  and  t'lo 
facts  of  nervous  structure  and  function  is  evident. 

Changes  in  nerve-vesicles  are  the  objective  correlatives  of 
what  we  know  subjectively  as  feelings;  and  the  discharges 
through  fibres  that  connect  nerve-vesicles  are  the  objec- 
tive correlatives  of  what  we  know  subjectively  as  relations 
between  feelings.  It  follows  that  just  as  the  association  of  a 
feeling  with  its  class,  order,  genus,  and  species,  group  within 
group,  answers  to  the  localization  of  the  nervous  change 
within  some  great  mass  of  nerve-vesicles,  within  some  part 
of  that  mass,  within  some  part  of  that  part,  &c. ;  so  the  asso- 
ciation of  a  relation  with  its  class,  order,  genus,  and  species, 
answers  to  the  localization  of  the  nervous  discharge  within 
some  great  aggregate  of  nerve-fibres,  within  some  division 
of  that  aggregate,  within  some  bundle  of  that  division. 
Moreover,  as  we  before  concluded  that  the  association  of 
each  feeling  with  its  exact  counterparts  in  past  experience, 
answers  to  the  re-excitation  of  the  same  vesicle  or  vesicles; 
so  here  we  conclude  that  the  association  of  each  relation  with 
its  exact  counterparts  in  past  experience,  answers  to  the  re- 
excitation  of  the  same  connecting  fibre  or  fibres.  And  since, 
on  the  recognition  of  any  object,  this  re-excitation  of  the 
plexus  of  fibres  and  vesicles  before  jointly  excited  by  it,  an- 
swers to  the  association  of  each  constituent  relation  and  each 
constituent  feeling  with  the  like  relation  and  the  like  feeling 
contained  in  the  previous  consciousness  of  the  object;  it  is 
clear  that  the  whole  process  is  comprehended  under  the 
principle  alleged.  If  the  recognized  object,  now  lacking  one 
of  its  traits,  arouses  in  consciousness  an  ideal  feeling  answer- 
ing to  some  real  feeling  which  this  trait  once  aroused; 


THE  ASSOCIABILITY  OF  RELATIONS.  271 

the  cause  is  that  along  with  the  strong  discharge  through 
the  whole  plexus  of  fibres  and  vesicles  directly  excited, 
there  is  apt  to  go  a  feeble  discharge  to  those  vesicles  which 
answer  to  the  missing  feeling,  through  those  fibres  which 
answer  to  its  missing  relations,  involving  a  representation 
of  the  feeling  and  its  relations. 


CHAPTER  IX. 


PLEASUKES   AND   PADTS. 


§  122.  The  foregoing  chapters  contain  such  an  outline 
of  the  Inductions  of  Psychology  as  the  plan  of  this  work 
requires.  To  fill  in  this  outline  would  take  more  space 
than  can  be  afforded,  and  would  too  much  interrupt  the 
general  argument. 

There  is,  however,  one  other  side  of  mental  pheno- 
mena as  inductively  generalized,  which  cannot  be  omitted 
without  leaving  this  outline  incomplete.  Thus  far  we  have 
spoken  of  Feelings  as  central  or  peripheral,  as  strong  or 
weak,  as  vague  or  definite,  as  coherent  or  incoherent,  as 
real  or  ideal ;  and  where  we  have  considered  them  as  differ- 
ing in  quality,  the  differences  named  have  been  such  as  do 
not  connote  anything  more  than  a  state  of  indifference  in 
the  subject  of  them — a  passive  receptivity.  But  there  are 
certain  common  characters  in  virtue  of  which  Feelings  other- 
wise quite  unlike,  range  themselves  together  either  under 
the  head  of  pleasurable  or  under  the  head  of  painful.  Just 
as  we  saw  that  the  division  of  Feelings  into  real  and  ideal, 
which  is  based  on  a  functional  difference,  cuts  across  the 
divisions  into  central,  ento-peripheral,  and  epi-peripheral, 
which  are  based  on  structural  differences;  so  here  we  may 
see  that  the  division  of  Feelings  into  agreeable  and  disagree- 
able, traverses  all  other  lines  of  demarkation — groups  into 

one  heterogeneous  assemblage  sensations  from  all  parts  and 

272 


PLEASURES  AND  PAINS.  273 

emotions  of  various  kinds,  together  witli  the  ideas  of  such 
sensations  and  emotions,  and  into  another  assemblage  sensa- 
tions and  emotions,  real  and  ideal,  similarly  heterogeneous. 
To  treat  fully  of  consciousness  under  this  further  aspect, 
would  carry  us  still  more  widely  out  of  our  course;  for  the 
phenomena  of  Pleasure  and  Pain  are  perhaps  the  most 
obscure  and  involved  which  Psychology  includes.  It  must 
suffice  to  set  down  here  what  appear  to  be  the  essentials. 

§  123.  Pleasures  and  Pains  are  concomitants  of  certain 
states,  local  or  general — certain  actions,  I  was  about  to 
say,  but  since  pains  of  one  class  accompany  what  we  dis- 
tinguish as  inactions  (though  these  can  never  be  absolute 
while  the  life,  general  or  local,  continues)  it  is  better  to  use 
the  word  states.  Kot  that  all  living  states,  either  of  the 
whole  organism  or  of  any  organ,  are  accompanied  by  plea- 
sures or  pains;  for  many  of  them,  as  those  of  the  viscera 
during  the  normal  discharge  of  their  functions,  yield  to 
consciousness  no  feelings  of  any  kind;  and  there  are  also 
feelings  yielded  by  higher  organs  that  are  neither  pleasure- 
able  nor  painful,  as  an  ordinary  sensation  of  touch.  But 
while  certain  states  cause  no  feelings,  and  other  states 
cause  indifferent  feelings,  the  feelings  distinguished  as  plea- 
surable and  painful  manifestly  result  from  states  of  some 

kind;  and  the  question  is What  are  the  states  which 

yield  Pains  and  what  are  the  states  which  yield  Pleasures? 

As  implied  by  the  parenthetical  remark  just  made,  there 
are  pains  arising  from  states  of  inaction — pains  we  call 
them,  since  we  here  use  the  word  as  antithetical  to  plea- 
sures; but  they  are  best  known  as  discomforts  or  cravings, 
from  having  a  quality  in  which  they  are  like  one  another  and 
unlike  pains  commonly  so-called.  Let  us  glance  at  their 
leading  kinds.  The  cravings  due  to  inaction  of 

the  organs  yielding  the  higher  epi-peripheral  feelings,  are 
rarely  strong  because  these  organs  are  rarely  quite  inactive. 
Sensations  of  touch  being  incessant,  the  want  of  them  is 


2Y4  THE  INDUCTIONS  OF  PSYCHOLOGY. 

never  felt.  Sounds  are  so  habitually  heard  everywhere  that 
few  experience  the  desire  for  them  which  follows  continued 
silence.  Only  after  being  confined  for  days  in  the  dark  does 
there  come  a  positive  longing  for  light  and  colour.  The 
absence  of  odours  never  becomes  an  element  of  discomfort. 
And  though  after  persistent  denial  of  them  certain  natural 
tastes,  as  those  of  sweetness,  and  still  more  certain  acquired 
tastes,  as  those  of  alcohol  and  tobacco,  come  to  be  much 
desired;  yet  the  cravings  for  them  are  by  no  means  so 
strong  as  the  accompanying  ento-peripheral  cravings  with 
which  they  are  apt  to  be  confounded.  Among 

cravings  of  the  ento-peripheral  order  occur  some  of  the 
strongest.  Inaction  of  the  alimentary  canal  is  soon 
followed  by  hunger;  and  if  the  inaction  continues,  this, 
rising  presently  to  a  distinct  discomfort,  eventually  passes 
into  something  more  intense.  So,  too,  that  allied  in- 
action due  to  deficiency  of  liquid  in  the  ingesta,  brings 
on  the  longing  we  call  thirst,  which  also  may  rise  to 
a  great  height.  And  similarly  with  the  abnormal  ap- 
petites for  habitual  stimulants.  We  must  not  omit 
the  disagreeable  state  of  consciousness  caused  by  muscular 
inaction.  The  irritation  that  accompanies  enforced  qui- 
escence, often  very  manifest  in  children,  must  be  numbered 
among  the  ento-peripheral  cravings.  There  remain 

the  dissatisfactions  brought  on  by  certain  inactions  of  the 
central  organs  of  the  nervous  system — the  emotional  crav- 
ings. Solitude,  necessitating  quiescence  of  the  faculties  ex- 
ercised in  holding  converse  with  our  fellow-beings,  leads  by 
and  by  to  great  misery.  The  entire  absence  of  marks  of  ap- 
proval from  those  around  us,  causes  a  state  of  conscious- 
ness difficult  to  bear;  and  persons  accustomed  to  positive 
applause  feel  unhappy  when  it  is  not  given.  In  like  manner, 
the  faculties  which  have  the  closer  human  relations  for  their 
sphere,  yield  their  pains  of  inaction — the  yearnings  of  the 
affections.  To  meet  an  obvious  criticism  it  may  be  re- 
marked that  the  intenser  forms  of  distress  caused  by  the 


PLEASURES  AND  PAINS.  275 

breaking  of  these  closer  human  relations,  are  not  to  be  in- 
cluded among  emotional  cravings;  but  result  from  the 
representation  of  a  future  in  which  such  cravings  will  never 
be  satisfied. 

"We  now  turn  to  pains  of  the  opposite  kind — the  states 
of  consciousness  that  accompany  excessive  actions.  Of 
these  there  are,  of  course,  classes  corresponding  to  the 
above-described  classes  of  the  pains  of  deficient  actions. 
They  must  be  briefly  enumerated.  Among  the 

epi-peripheral  feelings,  those  which  originate  on  the  general 
surface  are  conspicuously  capable  of  being  raised  to  a  pain- 
ful strength.  The  sensation  of  heat  much  intensified  passes 
into  the  unbearable  sensation  we  know  as  burning  or  scald- 
ing. Pressure  against  a  hard  body  produces  by  its  excess 
an  intolerable  state  of  consciousness.  Doubtless,  too,  all 
smarts  and  aches  caused  by  bruises,  wounds,  and  other  in- 
juries of  the  surface,  imply  the  undue  excitement  of  nerves 
which  when  normally  excited  yield  the  normal  peripheral 
feelings.  Auditory  sensations  occasionally  rise  to  an  ex- 
treme that  cannot  be  borne  with  equanimity.  Persons  in 
the  cupola  from  which  a  cannon  is  fired,  or  those  in  a  belfry 
when  a  peal  is  being  rung,  have  vivid  experiences  of  this. 
It  is  not  often  that  visual  feelings  reach  a  height  which  is 
painful — in  men,  at  least,  whose  eyes  are  strong.  But  men 
whose  eyes  are  debilitated  cannot  look  at  the  sun  without 
suffering,  and  even  find  it  unpleasant  to  gaze  at  a  large  area 
of  bright  scarlet.  Olfactory  feelings,  often  exceedingly  dis- 
agreeable, do  not  become  positive  pains.  Inhaling  ammo- 
nia does,  indeed,  cause  a  kind  of  smart;  but  this,  arising 
not  in  the  olfactory  chamber  so  much  as  in  the  nostrils,  is 
rather  to  be  classed  as  an  intense  form  of  common  sensa- 
tion. Tastes,  too,  though  many  of  them  are  repugnant,  do 
not  become  painful  by  increase  of  strength;  nor  when  the 
repugnancy  exists  is  strength  always  a  needful  condition. 
On  the  one  hand,  such  a  taste  as  that  of  cod-liver  oil  is  dis- 
agreeable even  though  slight;  while,  on  the  other  hand, 
19 


276  THE  INDUCTIONS  OP  PSYCHOLOGY. 

sweetness  is  not  rendered  disagreeable  by  any  degree  of 
intensity.  Among    feelings    of    ento-peripheral 

origin,  the  connexion  between  pain  and  excess  of  action 
is  familiar.  Such  of  them  as  accompany  muscular  strains 
show  us  pains  reached  through  intensification  of  feelings 
which  when  moderate  are  not  painful:  the  distressing 
consciousness  of  extreme  effort  is  a  higher  degree  of  the 
ordinary  consciousness  of  effort.  But  passing  over  the 
ento-peripheral  pains  of  this  order,  it  is  to  be  remarked 
of  the  rest  that  they  arise  from  excessive  actions  in  organs 
whose  normal  actions  yield  no  feelings.  The  pains  conse- 
quent on  repletion  come  from  parts  which,  when  not  over- 
taxed, add  no  appreciable  elements  to  consciousness;  and  it 
is  thus  with  the  viscera  in  general.  The  like  may  be  said 
of  those  pains  initiated  within  the  limbs  which  are  not 
directly  due  to  excesses  of  action  of  the  limbs  themselves 
or  parts  of  them.  Such  pains,  consequent,  let  us  say,  on 
gout  or  on  a  local  disease,  imply  extreme  demands  made  on 
certain  local  structures  and  their  nerves,  which  when  not 
over-worked  originate  no  sensations.  The  central 

feelings  are  scarcely  in  any  case  made  painful  simply  by 
excess.  Normal  emotions  responding  to  the  various  normal 
activities,  do  not,  however  high  they  may  rise,  become  in- 
trinsically disagreeable.  We  have,  indeed,  occasional  allu- 
sion to  states  in  which  "  joy  is  almost  pain,"  showing  a 
perceived  approach  to  this  effect  of  excess;  but  if  pain  so 
caused  is  ever  actually  reached,  it  is  very  rarely. 

Thus  recognizing,  at  the  one  extreme,  the  negative  pains 
of  inactions,  called  cravings,  and,  at  the  other  extreme,  the 
positive  pains  of  excessive  actions,  the  implication  is  that 
pleasures  accompany  actions  lying  between  these  extremes. 
It  is  true  that  the  positive  or  negative  pain  attending  one 
or  other  of  the  extremes  is  missing  among  actions  of  certain 
orders ;  and  that  other  actions  may  be  named  which  are  dis- 
agreeable even  when  of  medium  intensity.  In  some  of  these 
cases  the  explanation  is  that  no  feeling  of  the  order  due  to 


PLEASURES  AND  PAINS.  277 

the  extreme  state  arises  because  the  extreme  state  is  not 
reached.  The  fact  that  from  the  kidneys  there  comes  no 
craving,  may  pair  off  with  the  fact  that  they  have  always 
work  to  do.  No  one  longs  for  tactual  impressions  for  the 
sufficient  reason  that  tactual  impressions  are  unceasing.  The 
emotions  that  go  along  with  the  successful  pursuit  of  the 
various  objects  of  life,  cannot  well  rise  from  a  pleasurable 
degree  to  a  painful  degree ;  since  the  environing  conditions 
which  cause  them  do  not  admit  of  the  required  progressive 
intensification.  Generally  speaking,  then,  pleasures  are  the 
concomitants  of  medium  activities,  where  the  activities  are 
of  kinds  liable  to  be  in  excess  or  in  defect;  and  where  they 
are  of  kinds  not  liable  to  be  excessive,  pleasure  increases 
as  the  activity  increases,  except  where  the  activity  is  either 
constant  or  involuntary. 

Though  we  thus  see  whereabouts  pleasure  is  to  be  found 
among  the  feelings,  it  must  be  admitted  that  its  relations 
remain  but  ill-defined.  The  conception  of  it  as  the  con- 
comitant of  an  activity  which  is  neither  too  small  nor  too 
great,  is  a  conception  open  to  a  criticism  akin  to  that  made 
by  Mr.  Mill  on  the  doctrine  of  Sir  W.  Hamilton,  that  "  plea- 
sure is  a  reflex  of  the  spontaneous  and  unimpeded  exertion 
of  a  power,  of  whose  energy  we  are  conscious,"  and  upon 
the  kindred  doctrine  of  Aristotle,  that  it  accompanies  the 
action  of  a  healthy  faculty  on  its  appropriate  object.     For 

there  arise  the  questions What  constitutes  a  medium 

activity?  What  determines  that  lower  limit  of  pleasur- 
able action  below  which  there  is  craving,  and  that  higher 
limit  of  pleasurable  action  above  which  there  is  pain? 

Is  it  possible  to  answer  these  questions,  and  is  it  possible 
to  answer  the  further  question — How  happen  there  to  be 
certain  feelings  (as  among  tastes  and  odours)  which  are 
disagreeable  in  all  degrees  of  intensity,  and  others  that  are 
agreeable  in  all  degrees  of  intensity  ?  Answers  are,  I  believe, 
to  be  found.  But  they  must  be  sought  in  a  region  which 
psychologists  have  not  explored.    If  we  study  feelings  only 


378  THE  INDUCTIONS  OF  PSYCHOLOGY. 

as  they  at  present  exist,  we  shall  find  no  solution;  but  we 
may  find  a  solution  if  we  turn  to  the  past  conditions  under 
which  feelings  have  been  evolved. 

§  124.  Let  us  first  glance  at  the  fact,  sufficiently  obvious 
and  sufficiently  significant,  that  the  extreme  states,  positive 
and  negative,  along  with  which  pains  occur,  are  states 
inconsistent  with  that  due  balance  of  the  functions  con- 
stituting health;  whereas  that  medium  state  along  with 
which  pleasure  occurs,  is  consistent  with,  or  rather  is  de- 
manded by,  this  due  balance.  This  we  may  see  a  priori. 
In  a  mutually-dependent  set  of  organs  having  a  consensus 
of  functions,  the  very  existence  of  a  special  organ  having  its 
special  function,  implies  that  the  absence  of  its  function 
must  cause  disturbance  of  the  consensus — implies,  too,  that 
its  function  may  be  raised  to  an  excess  which  must  cause 
disturbance  of  the  consensus — implies,  therefore,  that  main- 
tenance of  the  consensus  goes  along  with  a  medium  degree 
of  its  function.  The  a  priori  inference  involved,  that  these 
medium  actions  productive  of  pleasure  must  be  beneficial, 
and  the  extreme  actions  productive  of  pain  detrimental,  is 
abundantly  confirmed  d  posteriori  where  the  actions  are  of 
all-essential  kinds.    Here  are  a  few  cases. 

Intense  cold  and  intense  heat  both  cause  acute  suffering, 
and  if  the  body  is  long  exposed  to  them  both  cause  death; 
while  a  moderate  warmth  is  pleasurable  and  conduces  to 
physical  well-being.  Extreme  craving  for  food  accompanies 
a  hurtful  inaction  of  the  digestive  organs,  and  if  this  craving 
and  this  inaction  persist  the  result  is  fatal.  Conversely,  if 
solid  food,  or  liquid,  continues  to  be  swallowed  under  com- 
pulsion, regardless  of  the  painful  sensations  produced,  the 
effect  is  also  detrimental,  and  may  even  kill.  But  between 
these  pains  attending  deficient  and  excessive  action  there 
are  the  pleasures  of  eating,  which  are  keenest  when  the 
benefit  to  be  derived  is  greatest.  To  a  person  in  health 
duly  rested,  the  feeling  that  accompanies  absolute  inaction 


PLEASURES  AND  PAINS.  279 

of  the  muscles  is  unbearable;  and  this  inaction  is  injurious. 
On  the  other  hand,  extreme  exertion  of  the  muscles  in 
general  is  alike  distressing  and  productive  of  prostration, 
while  exertion  of  a  particular  muscle  pushed  to  a  painful 
excess,  leaves  a  temporary  paralysis,  and  occasionally,  by 
rupturing  some  of  the  muscular  fibres,  entails  prolonged 
uselessness.  Arrest  of  breathing  by  forcible  closure  of  the 
air-passages,  causes  an  intolerable  state  of  consciousness; 
and  life  soon  ceases  if  there  is  no  relief.  The  breathing  of 
foul  air  is  injurious  as  well  as  repugnant;  while  the  breath- 
ing of  air  that  is  exceptionally  fresh  and  pure,  is  both  plea- 
surable and  physically  advantageous.  So,  too,  is  it  with 
the  feelings  caused  by  contacts  with  objects.  Though,  as 
above  pointed  out,  we  cannot  be  debarred  from  these,  and 
therefore  have  no  craving  for  them  and  little  or  no  pleasure 
in  them,  yet  we  are  liable  to  excesses  of  them  and  the  ac- 
companying pains;  and  these  pains  are  the  correlatives  of 
detrimental  results — crushings,  and  bruises,  and  lacerations. 
It  is  even  so  with  extremely  strong  tastes  and  smells.  The 
intense  vegetal  bitters  are  poisonous  in  any  considerable 
quantities,  and  the  intensest  are  poisonous  in  very  small 
quantities.  Powerful  acids,  too,  are  poisonous — being, 
indeed,  immediately  destructive  of  the  membranes  they 
touch.  And  gases  that  violently  irritate  when  inhaled,  as 
concentrated  ammonia,  or  as  pure  chlorine,  or  as  hydro- 
chloric acid,  work  deleterious  effects. 

These  facts  should  of  themselves  suiRce  to  produce  the 
conviction,  spite  of  apparent  exceptions,  that  pains  are 
the  correlatives  of  actions  injurious  to  the  organism,  while 
pleasures  are  the  correlatives  of  actions  conducive  to  its 
welfare.  We  need  not,  however,  rest  satisfied  with  an  in- 
duction from  these  instances  yielded  by  the  essential  vital 
functions;  for  it  is  an  inevitable  deduction  from  the 
hypothesis  of  Evolution,  that  races  of  sentient  creatures 
could  have  come  into  existence  under  no  other  con- 
ditions. 


280  THE  INDUCTIONS  OP  PSYCHOLOGY. 

§  125.  If  we  substitute  for  the  word  Pleasure  the  equiva- 
lent phrase — a  feeling  which  we  seek  to  bring  into  con- 
sciousness and  retain  there,  and  if  we  substitute  for  the 
word  Pain  the  equivalent  phrase — a  feeling  which  we  seek 
to  get  out  of  consciousness  and  to  keep  out;  we  see  at  once 
that,  if  the  states  of  consciousness  which  a  creature  endea- 
vours to  maintain  are  the  correlatives  of  injurious  actions, 
and  if  the  states  of  consciousness  which  it  endeavours 
to  expel  are  the  correlatives  of  beneficial  actions, 
it  must  quickly  disappear  through  persistence  in  the  in- 
jurious and  avoidance  of  the  beneficial.  In  other  words, 
those  races  of  beings  only  can  have  survived  in  which,  on 
the  average,  agreeable  or  desired  feelings  went  along  with 
activities  conducive  to  the  maintenance  of  life,  while  dis- 
agreeable and  habitually-avoided  feelings  went  along  with 
activities  directly  or  indirectly  destructive  of  life ;  and  there 
must  ever  have  been,  other  things  equal,  the  most  numer- 
ous and  long-continued  survivals  among  races  in  which 
these  adjustments  of  feelings  to  actions  were  the  best,  tend- 
ing ever  to  bring  about  perfect  adjustment. 

If  we  except  the  human  race  and  some  of  the  highest 
allied  races,  in  which  foresight  of  distant  consequences  in- 
troduces a  complicating  element,  it  is  undeniable  that  every 
animal  habitually  persists  in  each  act  which  gives  pleasure, 
80  long  as  it  is  does  so,  and  desists  from  each  act  which  gives 
pain.  It  is  manifest  that,  for  creatures  of  low  intelligence, 
unable  to  trace  involved  sequences  of  effects,  there  can  be 
no  other  guidance.  It  is  manifest  that  in  proportion  as  this 
guidance  approaches  completeness,  the  life  will  be  long ;  and 
that  the  life  will  be  short  in  proportion  as  it  falls  short  of 
completeness.  Whence  it  follows  that  as,  other  things 
equal,  the  longer-lived  individuals  of  any  species  will  more 
frequently  produce  and  rear  progeny  than  the  shorter-lived, 
the  descendants  of  the  one  must  tend  to  replace  those  of 
the  other — a  process  which,  equally  operative  among  the 
multiplying  families  of  these  surviving  descendants,  cannot 


PLEASURES  AND  PAINS.  281 

but  worK  towards  maintenance  and  improvement  of  the 
guidance. 

How  then,  it  will  be  asked,  does  it  happen  that  animals 
sometimes  die  from  eating  poisonous  plants,  or  surfeit  them- 
selves fatally  with  kinds  of  food  which,  though  wholesome 
in  moderate  quantities,  are  injurious  in  large  quantities? 
The  reply  is  that,  by  natural  selection,  the  guidance  of  plea- 
sures and  pains  can  be  adjusted  only  to  the  circumstances 
of  the  habitat  within  which  the  special  type  has  been  evolved. 
SurAdval  of  the  fittest  cannot  bring  the  inclinations  and  aver- 
sions into  harmony  with  unf  elt  conditions.  And  since  each 
species  under  pressure  of  increasing  numbers  is  ever  thrust- 
ing itself  into  adjacent  environments,  its  members  must  from 
time  to  time  meet  with  plants,  with  prey,  with  enemies^ 
with  physical  actions,  of  which  neither  they  nor  their 
ancestors  have  had  experience,  and  to  which  their  feelings 
are  unadapted.  !Not  only  by  migration  into  other  habitats, 
but  also  by  changes,  inorganic  and  organic,  within  its  own 
habitat,  does  each  species  suffer  from  failures  of  adjustment. 
But  mis-adjustment  inevitably  sets  up  re-adjustment.  Those 
individuals  in  whom  the  likes  and  dislikes  happen  to  be 
most  out  of  harmony  with  the  new  circumstances,  are  the 
first  to  disappear.  And  if  the  race  continues  to  exist  there 
cannot  but  arise,  by  perpetual  killing-off  of  the  least 
adapted,  a  variety  having  feelings  that  serve  as  incentives 
and  deterrents  in  the  modified  way  required. 

We  will  consider  more  at  length,  in  connection  with  our 
own  race,  the  qualifications  with  which  the  general  law  must 
be  received. 

§  126.  Mankind  shows  us  in  many  conspicuous  ways,  the 
failures  of  adjustment  that  follow  changes  of  environing 
conditions — not  so  much  the  changes  which  migrations  in- 
volve, though  these  too  are  to  be  taken  into  account,  but 
the  changes  caused  by  the  growth  of  large  societies. 

Pre-historic  men,  like  men  as  we  find  them  still  in  many 


282  THE  INDUCTIONS  OF  PSYCHOLOGY. 

parts  of  the  Earth,  had  feelings  congruous  with  the  wander- 
ing predatory  life,  only  incipiently  social,  which  they  had  to 
lead.  Inadequate  supply  of  wild  food  compelled  some  of 
their  descendants  to  become  pastoral  and  agricultural:  and 
these  multiplied  into  populous  tribes  and  eventually  into 
settled  communities.  They  were  thereby  cut  off  from  activi- 
ties like  those  of  the  men  whose  characters  they  inherited, 
and  were  forced  into  activities  to  which  their  inherited 
characters  furnished  no  incentives.  Throughout  the  course 
of  civilization  this  has  been,  and  continues  in  large 
measure  to  be,  the  source  of  discordances  between  in- 
clinations and  requirements.  On  the  one  hand,  there 
still  survive  those  feelings,  quite  proper  to  our  remote 
ancestors,  which  find  their  gratification  in  the  de- 
structive activities  of  the  chase  and  in  warfare — feelings 
which,  anti-social  as  is  the  conduct  they  prompt,  in- 
directly cause  numerous  miseries.  On  the  other  hand, 
persistent  and  monotonous  labour  has  been  rendered  by 
the  pressure  of  population  a  necessity;  and  though  to 
civilized  men  work  is  by  no  means  so  repugnant  as  to 
savages,  and  to  a  few  is  even  a  source  of  pleasure,  yet  the 
re-adjustment  has  at  present  gone  by  no  means  so  far  that 
pleasure  is  habitually  found  in  the  amount  of  work  habitu- 
ally required.  Further,  it  is  to  be  observed  that  many  of  the 
industrial  activities  which  the  struggle  for  existence  has 
thrust  on  the  members  of  modem  societies,  are  in-door 
activities — activities  not  only  unresponded  to  by  the  feel- 
ings inherited  from  aboriginal  men,  but  in  direct  conflict 
with  those  more  remotely  inherited  and  deeply  organized 
feelings  which  prompt  a  varied  life  in  the  open  air. 

Secondary  discordances,  and  resulting  derangements  of 
the  normal  guidance,  are  indirectly  caused  by  this  enforced 
persistence  in  habits  of  life  at  variance  with  the  needs  of  the 
constitution.  A  sedentary  occupation  pursued  for  years  in  a 
confined  air,  regardless  of  protesting  sensations,  brings  about 
a  degenerate  physical  state  in  which  the  inherited  feelings 


PLEASURES  AND  PAINa  283 

are  greatly  out  of  harmony  with  the  superinduced  require- 
ments of  the  body.  Desired  foods,  originally  appropriate, 
become  indigestible.  An  air  pleasure-giving  by  its  fresh- 
ness to  those  in  vigour,  brings  colds  and  rheumatisms. 
Amounts  of  exertion  and  excitement  naturally  healthful  and 
gratifying,  are  found  injurious.  All  which  evils,  due  though 
they  are  to  continued  disregard  of  the  guidance  of  inherited 
feelings,  come  eventually  to  be  mistaken  for  proofs  that  the 
guidance  of  inherited  feelings  is  worthless. 

There  is  yet  another  derivative  cause  of  derangement. 
Men  whose  circumstances  compel  them  day  after  day  to  call 
certain  powers  into  undue  and  painful  action,  while  they  are 
shut  out  from  most  of  the  pleasures  accompanying  the  due 
action  of  other  powers,  are  liable  to  carry  too  far  such  plea- 
surable actions  as  remain  to  them.  After  disagreeable  states 
of  consciousness  long  submitted  to,  an  agreeable  state  of 
consciousness  is  received  with  eagerness ;  and  in  the  absence 
of  alternative  agreeable  states  is  maintained  by  too  great  a 
persistence  in  the  action  which  brings  it.  Hence  arise 
various  kinds  of  excess.  Feelings  which  would  not  have 
misled  men  if  all  their  other  feelings  had  had  appropriate 
spheres  of  action,  become  misleading  when  these  other  feel- 
ings are  repressed.  And  then  there  is  charged  upon  the 
active  feelings  that  misguidance  which  has  arisen  from  en- 
forced disobedience  to  the  rest. 

The  rectification  of  these  profound  and  multitudinous  dis- 
cordances by  the  re-equilibration  of  constitution  and  condi- 
tions, proceeds  in  the  human  race  very  slowly,  for  several 
reasons.    They  are  these.  As  pointed  out  in  the 

Prmciples  of  Biology^  §  166,  the  fitting  of  an  organism 
to  new  circumstances  becomes  less  and  less  easily  effected  by 
survival  of  the  fittest  in  proportion  as  the  organism  becomes 
complex.  This  is  illustrated  most  clearly  among  ourselves. 
There  are  so  many  kinds  of  superiorities  which  severally 
enable  men  to  survive,  notwithstanding  accompanying  in- 
feriorities, that  natural  selection  cannot  by  itself  rectify  any 


284  THE  INDUCTIONS  OP  PSYCHOLOGY. 

particular  unfitness :  especially  if,  as  usually  happens,  there 
are  co-existing  unfitnesses  which  all  vary  independently. 
Indirect  equilibration  can  play  but  a  secondary  part,  and  the 
change  having  to  be  wrought  by  direct  equilibration,  or  the 
inheritance  of  functionally-produced  alterations,  is  slower 
than  it  would  otherwise  be.  Again,  the  conditions 

to  which  we  must  be  re-adapted  are  themselves  changing. 
Each  further  modification  of  human  nature  makes  possible  a 
further  social  modification.  The  environment  alters  along 
with  alteration  of  the  constitution.  Hence  there  is  required 
re-adjustment  upon  re-adjustment.  Once  more, 

such  help  to  re-adjustment  as  would  result  from  survival  of 
the  fittest  if  individuals  in  most  respects  ill-fitted  were 
allowed  to  disappear,  is  in  great  part  prevented.  Indeed, 
the  imbecile  and  idle  are  artificially  enabled  to  multiply  at 
the  expense  of  the  capable  and  industrious. 

In  the  case  of  mankind,  then,  there  has  arisen,  and  must 
long  continue,  a  deep  and  involved  derangement  of  the 
natural  connexions  between  pleasures  and  beneficial  actions 
and  between  pains  and  detrimental  actions — a  derangement 
which  so  obscures  these  natural  connexions  that  even  the 
reverse  connexions  are  supposed  to  obtain.  And  the  half- 
avowed  belief,  very  commonly  to  be  met  with,  that  painful 
actions  are  beneficial  and  pleasurable  actions  detrimental, 
has  been,  and  still  is,  upheld  by  creeds  which  present  for 
the  worship  of  men  a  Being  who  is  supposed  to  be  displeased 
with  them  if  they  seek  gratifications,  and  to  be  propitiated 
by  gratuitous  self-denials  and  even  by  self-tortures. 

§  127.  Here,  however,  we  accept  the  inevitable  corollary 
from  the  general  doctrine  of  Evolution,  that  pleasures  are 
the  incentives  to  life-supporting  acts  and  pains  the  deterrents 
from  life-destroying  acts.  Not  only  do  we  see  that  among 
inferior  sentient  creatures  this  guidance  is  undeniably  effi- 
cient, but  also  that  it  is  undeniably  efficient  in  ourselves,  so 
far  as  regards  the  functions  on  which  life  immediately 


PLEASURES  AND  PAINS.  285 

depends.  And  we  cannot  here  suppose  that  a  regulative 
system  efficient  for  all-essential  actions  has  to  be  reversed 
for  the  actions  growing  out  of  them. 

One  more  qualification  has  to  be  made.  We  are  apt 
to  take  for  granted  that  the  beneficial  actions  secured  must 
be  actions  beneficial  to  the  individual;  whereas  the  only 
necessity  is  that  they  shall  be  beneficial  to  the  race.  The 
two  are  by  no  means  identical.  Up  to  a  certain  point,  while 
the  individual  is  young  and  not  yet  fertile,  its  welfare  and 
the  welfare  of  the  race  go  together;  but  when  the  repro- 
ductive age  is  reached,  the  welfare  of  the  individual  and  of 
the  race  cease  to  be  the  same,  and  may  be  diametrically 
opposed.  In  fact  they  are  diametrically  opposed  more  fre- 
quently than  not.  I  do  not  refer  merely  to  those  cases  of 
asexual  genesis  prevalent  among  the  lower  types  of  animals, 
in  which,  by  the  breaking  up  of  its  body  into  two  or  more, 
the  individuality  of  the  parent  is  lost  in  the  individualities 
of  the  offspring;  but  I  refer  to  those  cases  of  sexual  genesis, 
very  general  among  invertebrate  animals,  in  which  the  death 
of  the  parents  is  a  normal  result  of  propagation.  In  the 
great  class  Insects,  the  species  of  which  out-number  all 
other  animal  species,  the  rule  is  that  the  male  lives  only 
until  a  new  generation  has  been  begotten,  and  that  the 
female  dies  as  soon  as  the  eggs  are  deposited,  or,  as  in  some 
cases,  leaves  the  dead  shell  of  her  body  to  be  a  protecting 
cover  to  the  eggs.  Here,  however,  each  new  generation 
does  not  depend  for  its  welfare  on  continued  life  of  the  old. 
Where,  as  among  the  higher  animals,  the  offspring  have  to  be 
fostered,  survival  of  the  fittest  must  establish  such  a  consti- 
tutional balance  that  obedience  to  the  feelings,  peripheral 
and  central,  which  secure  the  maintenance  of  the  species 
cannot  be  fatal  or  even  seriously  injurious.  And  where,  as 
in  the  highest  types,  successive  broods  or  successive  individ- 
uals are  produced  during  a  series  of  years,  and  especially 
where  the  successive  individuals  so  produced  have  to  be  fos- 
tered for  long  periods,  the  implied  satisfaction  of  the  feel- 


286  THE  INDUCTIONS  OP  PSYCHOLOGY. 

ings  must  be  consistent  with  parental  welfare.  If  we  cannot 
infer,  as  a  necessary  result  of  survival  of  the  fittest,  that  the 
guidance  of  the  feelings  is  here  beneficial  to  the  individual, 
we  can  at  any  rate  infer  that  it  is  not  detrimental. 

Thus,  considering  as  transitional  those  many  anomalies 
that  accompany  the  adaptation  of  the  human  race  to  social 
conditions,  and  taking  account  of  the  qualification  just 
made,  we  conclude  that,  up  to  the  reproductive  age,  pains 
are  the  concomitants  of  actions  injurious  both  to  the  indi- 
vidual and  to  the  species,  while  pleasures  are  the  concomi- 
tants of  actions  beneficial  both  to  the  individual  and  to  the 
species;  and  that  while,  after  reproduction  commences,  the 
same  relations  continue  to  hold,  the  additional  relations  be- 
tween feelings  and  actions  which  then  arise,  may  be  of  a 
reverse  kind,  but  that  the  reversal  cannot  obtain  among  the 
higher  types  of  sentient  beings. 

§  128.  A  few  words  must  be  added  on  one  further 
question — What  are  the  intrinsic  natures  of  Pleasures  and 
Pains,  psychologically  considered?  This  question  appears 
unanswerable,  and  may  eventually  prove  to  be  so.  With- 
out here  attempting  to  answer  it,  I  will  briefly  set  down 
three  allied  general  facts  which  indicate  the  direction  in 
which  an  answer  is  to  be  found,  if  there  is  one. 

Pleasures  to  a  large  extent,  and  Pains  to  some  extent,  are 
separate  from,  and  additional  to,  the  feelings  with  which  we 
habitually  identify  them.  If  I  hear  a  sound  of  beautiful 
quality,  an  agreeable  state  of  consciousness  is  produced; 
but  if  this  sound  is  unceasing,  or  perpetually  repeated,  the 
state  of  consciousness  loses  its  agreeableness  without  other- 
wise changing.  A  glow  of  delight  accompanies  the  sight 
of  a  fine  colour;  but  after  having  the  colour  before  the  eyes 
for  a  long  time  there  remains  only  the  consciousness  of  its 
quality — the  delight  is  gone.  Similarly,  if  I  go  on  tasting 
something  sweet,  there  comes  a  time  when  the  gratification 
ends,  though  the  sense  of  sweetness  continues.    Doubtless 


PLEASURES  AND  PAINS.  287 

the  sense  of  sweetness  itself  eventually  becomes  deadened; 
but  the  gratification  gives  place  to  nausea  before  this 
happens.  Among  Pains  the  parallel  fact  is  less 

conspicuous;  but  it  is  not  difficult  to  perceive  that  along 
with  the  localized  pain,  say  of  a  bruise  or  a  burn,  there 
goes  an  element  of  distress  that  is  not  localized. 

The  second  of  these  allied  truths,  illustrations  of  which 
serve  in  part  to  re-illustrate  the  first,  is  that  Pleasures  and 
Pains  may  be  acquired — may  be,  as  it  were,  superposed  on 
certain  feelings  which  did  not  originally  yield  them. 
Smokers,  snuff-takers,  and  those  who  chew  tobacco,  furnish 
familiar  instances  of  the  way  in  which  long  persistence  in  a 
sensation  not  originally  pleasurable,  makes  it  pleasurable — 
the  sensation  itself  remaining  unchanged.  The  like  happens 
with  various  foods  and  drinks,  which,  at  first  distasteful,  are 
afterwards  greatly  relished  if  frequently  taken.  Common 
sayings  about  the  effects  of  habit  imply  recognition  of  this 
truth  as  holding  with  feelings  of  other  orders.  That 

acute  pain  can  be  superinduced  on  feelings  originally  agree- 
able or  indifferent,  we  have  no  proof.  But  we  have  proof 
that  the  state  of  consciousness  called  disgust  may  be  made 
inseparable  from  a  feeling  that  was  once  pleasurable.  The 
extreme  repugnances  shown  by  children  to  the  sweet  things 
given  them  along  with  medicines,  are  illustrations;  and  pro- 
bably nearly  every  one  can  furnish  from  his  own  experience 
some  instance  of  acquired  aversion  of  another  order. 

The  third  of  these  allied  facts  is  that  Pleasures  are  more 
like  one  another  than  are  the  feelings  which  yield  them, 
and  that  among  Pains  we  may  trace  a  parallel  resemblance. 
The  wave  of  delight  produced  by  the  sight  of  a  grand  land- 
scape, is  qualitatively  much  the  same  as  that  produced  by 
an  expressive  musical  cadence.  There  is  close  kinship  be- 
tween the  agreeable  feelings  aroused,  the  one  by  a  kind 
word  and  the  other  by  a  highly  poetical  thought.  Nay,  it 
needs  but  to  mark  the  accompanying  expression  of  face, 
to  perceive  that  even  the  pleasure  which  an  exquisite  per- 


288  THE  INDDCTIONS  OP  PSYCHOLOGY. 

fume  yields  is  to  a  considerable  extent  of  the  same  nature. 
Indeed,  the  frequent  application  of  the  words  sweet,  delici- 
ous, &c.,  to  things  and  acts  of  all  kinds  that  yield  great 
pleasure,  shows  that  this  similarity  is  habitually  recog- 
nized. Pains  display  this  kinship  still  more 
conspicuously.  Though  the  ordinary  feelings  of  heat,  of 
pressure,  and  of  muscular  tension,  resemble  one  another 
but  little,  yet  when  they  are  severally  raised  to  high  in- 
tensities the  resulting  pains  are  nearly  allied.  Indeed,  there 
is  an  obvious  family  likeness  among  all  the  peripheral  pains 
when  intense,  and  among  all  the  central  pains  when  intense. 
These  three  general  facts  taken  together,  warrant  the 
suspicion  that  while  Pleasures  and  Pains  are  partly  con- 
stituted of  those  local  and  conspicuous  elements  of  feeling 
directly  aroused  by  special  stimuli,  they  are  largely,  if 
not  mainly,  composed  of  secondary  elements  of  feeling 
aroused  indirectly  by  diffused  stimulation  of  the  nervous 
system.  In  a  future  part  of  this  work  we  may  find  further 
reasons  for  believing  this. 


PART    III. 
GENERAL   SYNTHESIS. 


CHAPTER  I. 

LIFE   AND    MIND    AS    COBRESPONDENCE.* 

§  129.  Having  in  the  first  part  of  this  work  contem- 
plated those  facts  of  nervous  structure  and  function  which 
form  the  data  of  Psychology;  and  having,  in  the  part  just 
closed,  grouped  together  the  inductions  drawn  from  a 
general  survey  of  mental  states  and  processes;  we  are  pre- 
pared for  a  deductive  interpretation.  The  field  of  inquiry 
which  we  incidentally  entered  in  the  last  chapter,  when 
seeking  an  explanation  of  the  phenomena  of  pleasure  and 
pain,  we  have  now  to  explore  systematically  throughout  its 
whole  extent. 

If  the  doctrine  of  Evolution  is  true,  the  inevitable  impli- 
cation is  that  Mind  can  be  understood  only  by  observing 
how  Mind  is  evolved.  If  creatures  of  the  most  elevated 
kinds  have  reached  those  highly  integrated,  very  defi- 
nite, and  extremely  heterogeneous  organizations  they  pos- 
sess, through  modifications  upon  modifications  accumulated 
during  an  immeasurable  past — if  the  developed  nervous 
•  This  Chapter  stands  in  place  of  five  chapters  which,  in  the  original 
edition  of  this  work,  prepared  the  way  for  the  General  Synthesis.  The 
first  of  them,  on  Method,  I  hope  eventually  to  include  in  an  introduction 
to  First  Principles.  The  others  are  now  embodied  in  Part  I.  of  the 
Principles  of  Biology.  Except  by  the  omission  of  these  introductory 
chapters,  the  General  Synthesis  remains  in  substance  unchanged ;  but  it 
has  been  much  improved  in  expression. 
20  291 


292  GENERAL  SYNTHESIS. 

systems  of  such  creatures  have  gained  their  complex 
structures  and  functions  little  by  little;  then,  necessarily, 
the  involved  forms  of  consciousness  which  are  the  corre- 
latives of  these  complex  structures  and  functions  must 
have  arisen  by  degrees.  And  as  it  is  impossible  truly  to 
comprehend  the  organization  of  the  body  in  general,  or  of 
the  nervous  system  in  particular,  without  tracing  its  suc- 
cessive stages  of  complication;  so  it  must  be  impossible  to 
comprehend  mental  organization  without  similarly  tracing 
its  stages. 

Here,  then,  we  commence  the  study  of  Mind  as  objec- 
tively manifested  in  its  ascending  gradations  through  the 
various  types  of  sentient  beings. 

§  130.  From  what  point  are  we  likely  to  obtain  the 
widest  view  of  this  evolution?  How  shall  we  guide  our- 
selves towards  a  conception  general  enough  to  include  the 
entire  range  of  mental  manifestations,  up  from  creatures 
that  yield  but  the  faintest  traces  of  feeling  to  creatures 
having  intellects  and  emotions  like  our  own? 

In  pursuance  of  the  method  of  choosing  hypotheses,  we 
must  compare  mental  phenomena  with  the  phenomena  most 
like  them,  and  observe  what  character,  presented  by  no 
other  phenomena,  they  both  present.*  A  generalization 
uniting  two  different  but  allied  classes  of  facts,  necessarily 
unites  all  the  facts  contained  in  either  class.  Hence,  if  we 
find  a  formula  which  along  with  mental  evolution  includes 
the  evolution  nearest  akin  to  it,  we  shall,  by  implication, 
find  a  formula  comprehending  the  entire  process  of  mental 
evolution.  It  may  afterwards  be  needful  so  to  limit  this 
formula  that  mental  evolution  alone  is  expressed  by  it.  But 
we  shall  best  fulfil  the  requirements  of  clear  exposition  by 
first  exhibiting  mental  evolution  as  it  may  be  most  gene- 

*  Reference  is  here  made  to  the  omitted  chapter  on  Method,  named  in 
the  preceding  note. 


LIFE  AND  MIND  AS  CORRESPONDENCE.  293 

rally  conceived,  and  subsequently  specializing  the  concep- 
tion. 

The  phenomena  which  those  of  Mind  resemble  in  the 
greatest  degree  are  those  of  bodily  life.  "While  these 
classes  of  phenomena  are  intimately  related  to  one  another, 
they  are  related  to  other  classes  of  phenomena  in  compara- 
tively remote  ways.  Our  question,  therefore,  becomes — 
What  is  it  that  mental  life  and  bodily  life  have  in  common? 
And  this  amounts  to  the  question — What  distinguishes  Life 
in  general? 

§  131.  Thus,  in  looking  for  a  conception  of  mental  evolu- 
tion sufficiently  large  to  take  in  all  the  facts,  we  are  led 
back  to  the  definition  of  Life  reached  at  the  outset  of  the 
Principles  of  Biology. 

In  Part  L,  Chap.  IV.  of  that  work,  the  proximate  idea  we 
arrived  at  was  that  Life  is  "  the  definite  combination  of  hete- 
rogeneous changes,  both  simultaneous  and  successive."  In 
the  next  chapter  it  was  shown  that  to  develop  this  proxi- 
mate idea  into  a  complete  idea,  it  is  needful  to  recognize 
the  connexion  between  these  actions,  going  on  within  an 
organism  and  the  actions  going  on  without  it.  We  saw 
that  Life  is  adequately  conceived  only  when  we  think  of  it 
as  "the  definite  combination  of  heterogeneous  changes, 
both  simultaneous  and  successive,  in  correspondence  with 
external  co-existences  and  sequences."  Afterwards  this 
definition  was  found  to  be  reducible  to  the  briefer  defini- 
tion— "  The  continuous  adjustment  of  internal  relations  to 
external  relations;  "  and  though,  by  leaving  out  the  cha- 
racteristic of  heterogeneity,  this  definition  is  rendered  some- 
what too  wide,  so  that  it  includes  a  few  non-vital  phenomena 
which  simulate  vitality,  yet  practically  no  error  is  likely  to 
result  from  its  use. 

That  Life  consists  in  the  maintenance  of  inner  actions 
corresponding  with  outer  actions,  was  confirmed  on  further 
observing  how  the  degree  of  Life  varies  as  the  degree  of 


394  GENERAL  SYNTHESIS. 

correspondence.  It  was  pointed  out  that,  beginning  with 
the  low  life  of  plants  and  of  rudimentary  animals,  the 
progress  to  life  of  higher  and  higher  kinds  essentially  con- 
sists in  a  continual  improvement  of  the  adaptation  between 
organic  processes  and  processes  which  environ  the  organism. 
We  observed  how  along  with  complexity  of  organization 
there  goes  an  increase  in  the  number,  in  the  range,  in  the 
speciality,  in  the  complexity,  of  the  adjustments  of  inner 
relations  to  outer  relations.  And  in  tracing  up  the  increase 
we  found  ourselves  passing  without  break  from  the  phe- 
nomena of  bodily  life  to  the  phenomena  of  mental  life. 

We  have  now  to  start  afresh,  and  to  develop  the  general 
truth  there  briefly  indicated  into  a  combination  of  more 
special  truths. 

§  132.  In  doing  this  it  will  be  needful  to  begin  with  the 
life  of  forms  almost  too  simple  to  be  called  organisms,  that 
we  may  note  the  first  traces  of  differentiation  between  the 
vital  actions  we  class  as  physical  and  the  vital  actions  we 
class  as  psychical.  Though  throughout  we  shall  continue 
to  regard  these  two  classes  of  actions  as  falling  within  the 
one  class  marked  out  by  our  definition,  yet,  as  we  follow 
under  each  of  its  several  aspects  the  progress  of  the  corre- 
spondence between  the  organism  and  its  environment,  the 
reader  will  not  fail  to  observe  how  we  pass  from  the  physical 
to  the  psychical  the  moment  we  rise  above  the  correspond- 
ences that  are  few,  simple,  and  immediate. 


CHAPTER  n. 

THE   COREESPONDENCE    AS    DIRECT   AND    HOMOGENEOUS. 

§  133.  The  lowest  life  is  found  in  environments  of  un- 
usual simplicity.  Most  environments  present  both  co- 
existences and  sequences;  but  there  are  some  which,  for  a 
short  time,  present  co-existences  only;  and  in  these,  during 
this  short  time,  occur  the  least  developed  organic  forms.  Of 
those  classed  with  the  vegetal  kingdom,  may  be  instanced 
the  Yeast-plant,  and  the  Protococcus  ni/valis  or  red  snow 
alga.  Of  those  held  to  be  of  animal  nature,  the  Gregarina 
and  the  Hydatid  may  be  taken  as  samples. 

The  life  of  each  of  these  organisms  consists,  almost 
wholly,  of  a  few  contemporaneous  processes  adjusted  to  the 
co-existent  properties  of  the  medium  which  surrounds  it. 
The  yeast-plant  has  for  its  habitat  a  fluid  consisting  of 
water  holding  in  solution  certain  oxy-hydro-carbons,  some 
nitrogenous  matter,  oxygen,  and  probably  other  elements 
in  minor  proportions.  That  it  may  flourish,  the  water  must 
be  neither  very  hot  nor  very  cold;  and  light  must  be  ex- 
cluded. The  conditions  being  fulfilled,  the  yeast-plant  dis- 
plays what  we  call  vital  changes,  in  correspondence  with 
chemical  changes  among  the  substances  bathing  its  surface. 
The  cell  grows  and  multiplies;  the  fluid  ferments;  and 
while  the  fluid  continues  to  supply  the  needful  materials 
under  the  needful  conditions,  the  cell  continues  to  manifest 

the  same  phenomena.    But  let  the  temperature  be  consider- 

295 


296  GENERAL  SYNTHESIS. 

ably  raised,  or  some  of  the  ingredients  exhausted,  and  the 
actions  cease.  The  life,  limited  in  length  to  the  brief  period 
during  which  the  environment  remains  practically  uniform, 
exhibits  no  successive  changes  such  as  those  by  which  a 
shrub  responds  to  the  alternations  of  day  and  night,  and  of 
the  seasons.  Excluding  those  modifications  of  form  and 
size  which  are  the  necessary  concomitants  of  continued 
assimilation,  the  only  successive  changes  exhibited  by  the 
yeast-plant  in  common  with  the  higher  plants,  are  those 
which  end  in  the  formation  of  spores.  Determined  as  they 
probably  are  by  the  diminishing  quantities  of  the  materials 
needful  for  growth,  these  generative  actions  may  be  re- 
garded as  successive  changes  in  the  organism  corresponding 
with  successive  changes  in  the  environment;  and  most 
likely  there  is  no  organism  but  what,  in  addition  to  the 
simultaneous  processes  taking  place  in  it,  undergoes  a  serial 
process  of  this  character.  Evidently,  however,  the  two 
orders  of  changes,  answering  in  this  case  to  the  two  all- 
essential  functions  of  assimilation  and  reproduction,  exist 
under  their  simplest  forms  in  correspondence  with  the  sim- 
plest relations  in  the  environment;  and  ending  as  they  do 
with  that  new  state  of  the  environment  soon  arising,  the  life 
is  as  short  as  it  is  incomplex. 

It  is  needless  to  present  in  detail  each  of  the  other  cases 
named.  The  Protoooccus  nivalis  exists  in  snow — a  medium 
simple  and  constant  in  chemical  character,  and  restricted  in 
its  variations  of  temperature.  Reddening  by  its  rapid  multi- 
plication large  tracts  in  the  arctic  regions  in  a  single  night, 
during  which  the  circumstances  must  remain  almost  uni- 
form, this  minute  organism  exhibits  vital  processes  corre- 
sponding only  to  surrounding  co-existences ;  and  can  undergo 
scarcely  any  changes  corresponding  to  surrounding  se- 
quences. To  a  new  state  in  its  medium,  it  does  not  adapt 
itself  but  dies :  the  snow  melts  and  it  disappears.  Similarly 
with  the  Gh'egarina — a  single-celled  creature  which  inhabits 
the  intestines  of  certain  insects;  which  is  there  bathed  by 


CORKESPONDENCE  AS  DIRECT  AND  HOMOGENEOUS.  297 

nutritive  liquid;  which  is  kept  at  a  tolerably  constant  tem- 
perature; and  which  exists  no  longer  than  its  special 
environment  exists.  In  these  and  other  such  cases  the 
peculiarities  to  be  noted  are: — first,  that  the  actions  in  the 
organism  are  immediately  dependent  on  the  affinities  of  the 
elements  touching  it  on  all  sides;  and,  second,  that  the 
internal  changes  proceed  uniformly,  or  nearly  so,  because, 
during  the  brief  time  that  the  life  lasts,  the  external  rela- 
tions remain  uniform,  or  nearly  so.  The  correspondence  is 
at  once  direct  and  homogeneous.  The  disintegrating  matter 
and  the  matter  to  be  integrated,  being  everywhere  diffused 
through  the  environment,  it  results  that  all  the  agents  to 
which  the  vital  changes  stand  related,  are  not  only  in  contact 
with  the  organism,  but  continually  in  contact  with  it.  And 
hence  there  need  neither  those  motions  nor  locomotions, 
which,  where  they  occur,  involve  more  or  less  heterogeneity 
in  the  correspondence. 

§  134.  In  strictness,  no  other  forms  of  life  than  those 
conditioned  as  above  described,  can  be  said  to  exhibit  a 
correspondence  at  once  direct  and  homogeneous.  But  the 
transition  to  higher  forms  being  gradual,  it  is  impossible  to 
make  divisions  in  such  way  as  entirely  to  avoid  incongruities; 
and  on  the  whole,  it  seems  best  to  notice  here  a  class  of 
organisms  which,  while  they  exhibit  motion,  either  absolute 
or  relative,  do  so  with  comparative  uniformity.  The  simplest 
of  the  ciliated  animalcules;  the  most  regular  of  the  com- 
pound ciliated  organisms,  like  the  YoVoox  gldbator',  together 
with  the  Sponges  and  their  allies;  may  be  instanced  as  dis- 
playing life  of  this  order. 

Water,  either  fresh  or  salt,  being  in  all  these  cases  the 
medium  inhabited,  the  general  fact  to  be  observed  is,  that 
the  incipient  multiformity  of  the  vital  actions  is  in  corre- 
spondence with  the  incipient  multifonnity  of  the  environ- 
ment. Though,  from  a  human  point  of  view,  the  liquids  in 
which  the  yeast-plant  and  the  Gregarina  live  are  far  more 


298  GENERAL  SYNTHESIS. 

heterogeneous  than  the  water,  either  of  the  sea  or  of  a  pond; 
yet,  relatively  to  these  contained  organisms,  they  are  less 
heterogeneous.  For  every  portion  of  the  wort  bathing  the 
cell-wall  of  the  yeast-plant,  and  every  portion  of  the  nutri- 
tive emulsion  surrounding  the  Gregarina^  presents  the 
matter  to  be  assimilated;  but  every  portion  of  the  water  in 
which  diProtozoon  swims,  though  it  presents  oxygen,  does 
not  present  nutriment.  Evenly  diffused  as  the  food  of  the 
first  is,  and  irregularly  scattered  as  is  that  of  the  last,  the 
external  relations  must  be  more  homogeneous  to  the  one 
than  to  the  other.  And  manifestly,  an  organism  whose 
medium,  though  unceasingly  disintegrating  it,  is  not  un- 
ceasingly supplying  it  with  integrable  matter,  but  presents 
only  dispersed  atoms  of  integrable  matter,  must  either  tra- 
verse its  medium  with  such  velocity  as  shall  bring  it  in 
contact  with  the  requisite  quantity  of  integrable  matter,  or 
must  cause  the  medium  to  move  past  it  with  such  velocity — 
must  have  either  an  absolute  motion,  as  the  inf  usory  animal- 
cule, or  a  relative  motion,  as  the  sponge  towards  the  water  it 
draws  in  and  expels.  Thus  then,  the  addition  of  mechanical 
changes  to  the  changes  displayed  by  motionless  organisms,  is 
the  addition  of  new  internal  relations  in  correspondence  with 
new  external  relations. 

It  is,  however,  to  be  remarked,  that  the  processes  by  which 
movements  of  this  order  are  effected,  are  themselves  in  direct 
and  nearly  homogeneous  correspondence  with  almost  ever- 
present  properties  of  the  environment.  The  fact  that  the 
ciliary  action  of  fresh-water  creatures  ceases  when  they  are 
put  into  sea-water,  and  that  of  sea-water  creatures  when 
they  are  put  into  fresh-water;  the  fact  that  when  creatures 
displaying  it  have  been  killed,  the  ciliary  action  on  uninjured 
parts,  and  even  on  parts  that  have  been  cut  off,  continues  for 
a  long  time;  and  the  further  fact,  discovered  by  Yirchow, 
that  ciliary  motion  which  has  ceased  may  be  re-excited  by 
a  solution  of  caustic  potash;  unite  to  show  that  the  motion 
of  these  microscopic  hairs  is  caused  by  the  immediate  con' 


CORRESPONDENCE  AS  DIRECT  AND  HOMOGENEOUS.  299 

tact  of  something  in  the  environment — consists  of  a  suc- 
cession of  minute  internal  changes,  in  correspondence  with 
those  minute  recurring  actions  of  the  medium  which  the 
waving  of  the  cilia  themselves  involve.  And  the  occasional 
suspensions  of  the  motion  may  possibly  result  from  local 
deficiencies  in  the  medium,  of  those  materials  or  conditions 
that  determine  it;  in  which  case  this  slight  heterogeneity 
in  the  mechanical  changes  answers  to  a  slight  heterogeneity 
in  the  environment. 


CHAPTER  rCL 

THE   C50EEESP0NDENCE   AS   DIRECT   BUT   HETEB0GENE0U8. 

§  135.  The  advance,  of  which  we  have  just  marked  the 
first  steps,  from  a  correspondence  that  is  uniform  to  one 
that  is  varied,  begins  to  show  itself  distinctly  when  there 
occur  either  absolute  or  relative  changes  in  the  environment. 
Among  plants,  it  is  seen  when,  from  a  habitat  in  which  the 
needful  elements,  bathing  the  organism  on  all  sides,  are 
ever  presented  under  fit  conditions  for  absorption  by  it,  we 
pass  to  a  habitat  in  which  the  needful  elements,  though 
always  around,  are  not  always  presented  under  fit  conditions 
for  absorption.  And  among  animals,  it  is  seen  both  on 
passing  from  the  I^rotosoa  to  the  higher  aquatic  creatures, 
which  being  larger  and  therefore  needing  larger  prey  are 
in  the  condition  of  having  their  nutriment  less  uniformly 
diffused,  and  on  passing  from  aquatic  creatures  to  terrestrial 
ones,  to  which  the  less  uniform  diffusion  of  nutriment  is 
not  relative  only,  but  absolute.  The  result  is,  that  besides 
correspondence  with  a  few  ever-present  co-existences  in  the 
environment,  we  have  now  correspondence  with  a  few  se- 
quences in  it.    Let  us  glance  at  each  class  of  cases. 

§  136.  The  higher  plants,  requiring  not  only  carbonic  acid 

diluted  with  air,  but  light,  a  certain  temperature,  a  certain 

soil,  and  a  certain  quantity  of  moisture,  show  us  variations 

in  the  vital  actions  corresponding  with  variations  which  the 

800 


CORRESPONDENCE  AS  DIRECT  BUT  HETEROGENEOUS.  301 

environment  undergoes  in  respect  to  these  conditions — 
variations  answering  to  those  of  the  hour,  the  weather,  and 
the  seasons.  As  we  lately  saw,  the  lowest  life  continues 
only  so  long  as  its  environment  remains  practically  homo- 
geneous, both  in  Space  and  Time.  Life  a  degree  higher 
must  be  looked  for  in  organisms  displaying  changes  that 
correspond  with  the  most  general  changes  to  which  the 
environment  is  liable;  and  this  is  the  kind  of  life  exhibited 
by  the  vegetal  kingdom  at  large.  These  changes  in  light 
and  heat,  are  most  general  both  as  occurring  with  greater 
regularity  in  time  and  amount  than  any  others,  and  as 
aifecting  the  whole  mass  of  the  surrounding  medium. 
Being  periodic  and  universal,  as  well  as  comparatively  slow, 
they  produce  only  that  small  degree  of  heterogeneity  in  the 
environment,  answered  to  by  the  small  degree  of  hetero- 
geneity in  the  visible  changes  of  plant-life. 

It  should  be  added  that  the  greater  complexity  of  corre- 
spondences, and  therefore  greater  length  in  the  series  of 
correspondences,  which  these  higher  plants  display,  involves 
a  further  group  of  vital  processes.  The  long-continued 
growth  made  possible  by  the  better  adjustment  of  internal 
relations  to  external  relations,  implying,  as  it  does,  an  in- 
creasing remoteness  in  the  parts  of  the  organism  from  one 
another,  supposes  some  means  of  putting  the  remote  parts 
in  communication;  and  hence  a  circulatory  system.  Or, 
more  strictly,  it  may  be  said,  that  a  circulatory  system  is 
necessitated  by  increase  of  size,  joined  with  the  division  of 
the  environment  into  the  two  halves,  soil  and  air,  so  that 
the  only  respect  in  which  the  plant  shows  us  habitual  move- 
ments (those  of  sap)  answers  to  the  only  respect  in  which  the 
elements  in  its  environment  are  not  co-extensive  in  Space. 

§  137.  Turning  from  plants  to  plant-animals  or  zoophytes, 
we  see  that  while  in  them  there  are  general  successive 
changes  corresponding,  like  those  of  plants,  with  general 
successive    changes   in   their   environment,    they    exhibit 


302  GENERAL  SYNTHESIS. 

certain  special  changes,  corresponding  with  special  changes 
in  it.  Though  to  the  chemical,  thermal,  and  hygrometric 
actions  affecting  the  whole  mass  of  its  medium,  the  actions 
going  on  in  the  plant  slowly  respond,  they  do  not  respond 
to  surrounding  mechanical  actions;  as  those  of  a  wire- 
worm  gnawing  its  roots,  or  a  herbivore  browsing  on  its 
leaves.  But  the  most  conspicuous  of  a  zoophyte's  actions 
are  those  which  follow  the  touching  of  its  expanded  ten- 
tacles. To  a  relation  of  co-existence  between  tangible  and 
other  properties,  presented  in  a  particular  part  of  the  envi- 
ronment, there  corresponds,  in  the  organism,  a  relation  of 
sequence  between  certain  tactual  impressions  and  certain 
contractions.  Here  are  several  facts  to  be  noticed.  First, 
that  being  a  stationary  creature  whose  medium  does  not 
supply  matter  to  be  integrated  so  uniformly  as  it  supplies 
disintegrating  matter,  the  zoophyte  must  obtain  matter  to 
be  integrated  by  arresting  those  portions  here  and  there 
moving  through  its  medium;  and  doing  this  presupposes 
sensitiveness  and  contractility  connected  in  the  manner 
seen.  Second,  that  the  ability  to  respond,  not  simply  to 
the  co-existences  and  sequences  presented  by  the  whole 
mass  of  the  environment,  but  to  the  co-existences  and 
sequences  presented  by  particular  bodies  in  it,  is  an  advance 
in  the  correspondence ;  which  is  also  rendered  more  hetero- 
geneous by  the  addition. 

§  138.  Of  all  these  cases  however,  as  of  those  in  the 
last  chapter,  it  is  to  be  remarked,  that  the  correspondence 
between  internal  and  external  relations  extends  only  to 
external  relations  which  have  one  or  both  terms  in  contact 
with  the  organism.  The  processes  going  on  in  the  yeast- 
plant  cease  unless  its  cell-wall  is  bathed  by  the  saccharine 
and  other  matters  on  whose  affinities  they  depend.  The 
tree  must  have  its  carbonic  acid,  water,  earthy  salts,  ammo- 
nia, and  the  rest,  applied  directly  to  its  surface  in  the  pre- 
sence of  light  and  heat:  until  they  are  thus  applied  it 


CORRESPONDENCE  AS  DIRECT  BUT  HETEROGENEOUS.  303 

remains  inert.  And  so  too  among  the  lowest  animals,  the 
substances  to  be  assimilated  must  come  in  collision  with 
the  organism  before  any  correspondence  between  inner  and 
outer  changes  is  shown.  Alike  in  those  forms  of  life  whose 
environments  perpetually  present  the  disintegrating  and  in- 
tegrable  matters  under  the  requisite  conditions;  in  those 
whose  environments  perpetually  present  them,  but  under 
variable  conditions;  in  those  whose  environments,  though 
not  full  of  integrable  matter,  yet  contain  it  in  such  abund- 
ance that  mere  random  locomotion  brings  them  in  contact 
with  a  sufficiency;  and  in  those  whose  environments  con- 
tain it  in  moving  masses  so  numerous  that,  though  them- 
selves stationary,  chance  brings  them  as  many  as  they  want 
— alike  in  all  these  forms  of  life,  there  is  an  absence  of 
that  correspondence  between  internal  relations  and  distamt 
external  relations,  which  characterizes  more  highly-endowed 
forms. 


CHAPTER  IV. 

THE   CORRESPONDENCE   AS   EXTENDING   IN   SPACE. 

§  139.  On  ascending  from  the  lowest  types  of  life,  in 
which  the  adjustment  of  inner  relations  to  outer  relations 
is  thus  limited,  one  marked  manifestation  of  the  heighten- 
ing correspondence,  is  the  increasing  distance  at  which 
co-existences  and  sequences  in  the  environment  produce 
adapted  changes  in  the  organism.  This  progress  accompa- 
nies the  development  of  the  senses  of  smell,  sight,  hearing, 
&c.,  and  the  subsequent  development  of  the  intellect. 

There  is  reason  to  believe  that  the  susceptibilities  to 
odours,  colours,  and  sounds,  arise  by  degrees  out  of  that 
irritability  which  animal  tissue,  in  its  lowest  forms,  pos- 
sesses. The  saying  of  Democritus  that  all  the  senses  are 
modifications  of  touch,  modem  science  goes  far  to  confirm. 
Smelling  obviously  implies  the  contact  of  dispersed  particles 
with  a  specially-modified  part  of  the  organism — implies  that 
these  particles  are  so  carried  by  a  current  of  air  or  water  as 
to  impinge  on  this  modified  part.  Hearing  results  when  we 
feel  the  vibrations  of  the  air  lying  in  contact  with  our  bodies. 
As  the  skin  at  large  is  sensitive  to  a  succession  of  mecha- 
nical impulses  given  by  dense  matter;  so  certain  external 
auditory  structures,  easily  moved,  are  sensitive  to  a  far  more 
rapid  succession  of  mechanical  impulses  given  by  matter  of 
great  tenuity.  The  organ  of  sight,  again,  is  one  through 
which  the  pulses  or  undulations  of  a  yet  more  delicate 

304 


THE  CORRESPONDENCE  AS  EXTENDING  IN  SPACE.  305 

medium  are  impressed  on  us — undulations  incomparably 
faster  in  a  medium  incomparably  rarer.  Here  however,  as 
before,  contact  of  the  undulating  medium  with  an  adapted 
part  of  the  surface,  is  the  pre-requisite.  So  that  in  every 
case  the  sensation  produced  in  us  by  something  in  the 
environment,  involves  mechanical  action  on  some  part  of 
our  periphery.  In  every  case,  therefore,  touch,  of  a  coarse 
or  refined  order,  is  implied.  Ji[ot  only  do  the  conclusions  of 
physicists  support  this  doctrine  which  Democritus  taught; 
but  the  conclusions  of  biologists  do  the  like.  The  organs  of 
the  special  senses  are  every  one  of  them  developed  from  the 
dermal  system — are  modifications  of  that  same  tissue  in 
which  the  tactual  sense  in  general  is  seated.  Nor  is  this 
all.  It  is  a  remarkable  fact  that  the  eye  and  the  ear  are, 
in  their  types  of  structure,  morphologically  identical  with 
the  vibrisscB,  or  most  perfect  organs  of  touch.  {Principles 
of  Biology,  %^^h.) 

The  hypothesis  of  Evolution  implies  that  the  senses  in 
general  have  a  yet  deeper  basis  in  those  primordial  proper- 
ties of  organic  matter  which  distinguish  it  from  inorganic 
matter.  And  many  facts  point  to  the  conclusion  that  sensi- 
bility of  all  kinds  takes  its  rise  out  of  those  fundamental 
processes  of  nutrition  and  waste — integration  and  disinte- 
gration— in  which  Life,  in  its  primitive  form,  consists. 
Though  these  facts  do  not  suffice  to  establish  such  a  con- 
clusion, and  though  it  is  not  necessary  to  the  general  argu- 
ment that  they  should  be  here  given,  yet  they  form  so 
appropriate  an  introduction  to  the  subject  of  the  chapter 
that  it  will  be  well  to  devote  a  section  to  them. 

§  140.  In  the  lowest  animals,  which  are  so  little  organized 
as  to  be  almost,  if  not  quite,  homogeneous,  all  the  vital 
functions  are  diffused  throughout  the  whole  body.  Every 
part  exhibits  more  or  less  of  that  contractility  which  in 
higher  creatures  is  confined  to  the  muscles;  that  sensitive- 
ness which  they  show  only  in  the  nerves;  that  ability  to 


306  GENERAL  SYNTHESIS. 

absorb  nutriment  which  is  eventually  confined  to  the 
alimentary  canal;  that  excretory  action  afterwards  divided 
among  the  lungs,  skin,  and  kidneys;  that  reproductive 
power  which  with  them  is  localized.  Where,  as  in  the 
lowest  creatures  of  all,  the  body  consists  of  nothing  more 
than  a  structureless  substance,  and  where,  as  in  somewhat 
higher  and  larger  creatures,  the  body  is  little  else  than  an 
aggregation  of  like  units  of  nucleated  protoplasm,  there  is 
an  almost  complete  community  of  functions  throughout; 
and  only  as  fast  as  this  originally-uniform  tissue  becomes 
differentiated,  does  each  part  lose  the  power  of  subserving 
other  processes  than  its  habitual  one.  {Prvnciples  of  Biology, 
§§  57—60.) 

But  this  specialization  of  functions  does  not  altogether 
obliterate  the  original  community  of  functions.  Even  where 
"  the  physiological  division  of  labour  "  has  been  carried 
furthest,  many  of  the  tissues  retain  certain  powers  of  ful- 
filling one  another's  duties.  In  man,  skin  can  discharge  the 
office  of  mucous  membrane,  and  mucous  membrane  of  skin. 
Lungs  and  kidneys  can  to  some  extent  supply  each  other's 
shortcomings.  When  the  liver  fails,  biliary  matter  is  got 
rid  of  through  both  skin  and  kidneys.  In  salivation,  the 
glands  of  the  mouth  become  supplementary  excreting 
organs.  And  the  skin,  while  having  mainly  the  function  of 
ejecting  perspirable  matter,  yet  remains,  to  some  extent, 
both  a  respiratory  surface  and  a  surface  through  which 
nutriment  can  be  absorbed. 

Bearing  in  mind  this  general  fact,  that  throughout  the 
life  made  up  of  unintelligent  organic  processes,  hetero- 
geneity of  function  arises  out  of  a  primordial  homogeneity, 
the  traces  of  which  are  never  entirely  lost,  we  shall  be 
prepared  for  a  parallelism  of  method  and  results  in  the 
evolution  of  that  other  division  of  life  consisting  of  the 
sensory  and  motor  actions.  Here,  too,  we  may  look  for  a 
certain  community  of  function  throughout  the  whole  organ- 
ism— a  possession  by  the  whole  organism  of  those  suscepti- 


THE  CORRESPONDENCE  AS  EXTENDING  IN  SPACE.  3()7 

bilities  whicli  are  ultimately  located  and  developed  in  eyes, 
ears,  nose,  and  the  rest.  The  nucleated  protoplasm  which, 
by  one  process  of  differentiation  and  integration,  gives 
origin  to  the  internal  and  external  systems — the  visceral 
and  nervo-muscular  organs — must  have,  to  some  extent, 
the  powers  of  the  last  as  well  as  those  of  the  first.  Not 
only  the  fundamental  division  into  vegetative  and  animal 
functions,  but  the  subdivisions  of  each  of  these,  must  be 
regarded  as  specializations  of  the  various  properties  which 
every  part  of  the  elemental  tissue  possesses  in  some  slight 
degree.  Let  us  glance  at  the  genesis  of  the  several  senses 
from  this  point  of  view. 

Between  touch  and  assimilation  there  exists,  in  the  lowest 
creatures,  an  intimate  connexion.  In  many  Rhizopods  the 
tactual  surface  and  the  absorbing  surface  are  co-extensive. 
The  AmcBba,  a  speck  of  jelly  having  no  constant  form,  sends 
out,  in  this  or  that  direction,  prolongations  of  its  substance. 
One  of  these  meeting  with,  and  attaching  itself  to,  some 
relatively  fixed  object,  becomes  a  temporary  limb  by  which 
the  body  of  the  creature  is  drawn  forward;  but  if  this  pro- 
longation meets  with  some  relatively  small  portion  of 
organic  matter,  it  slowly  expands  its  extremity  round  this, 
slowly  contracts,  and  slowly  draws  the  nutritive  morsel  into 
the  mass  of  the  body,  which  collapses  round  it  and  pre- 
sently dissolves  it.  That  is  to  say,  the  same  portion  of 
tissue  is  at  once  arm,  hand,  mouth,  and  intestine — shows  us 
the  tactual  and  absorbent  functions  united  in  one.  And  if 
we  assume,  as  we  may  fairly  do,  that  the  behaviour  of  this 
protruded  part  when  its  end  touches  assimilable  matter, 
arises  from  some  molecular  action  set  up  between  the  two — 
is  caused  by  a  commencing  absorption  of  the  assimilable 
matter,  we  shall  see  a  still  closer  relation  between  the  pri- 
mordial sense  and  the  primordial  vegetative  function. 

In  the  same  phenomena  we  may  trace  a  nascent  sense  of 
taste.  The  ability  to  discriminate  between  organic  and 
inorganic  matter,  appears  to  be  possessed  in  some  degree 
21 


308  GENERAL  SYNTHESIS. 

even  by  the  simplest  animals.  Rhizopods  do  not  absorb 
indiscriminately  all  fragments  of  available  size;  nor  do  the 
tentacles  of  polypes  commonly  behave  in  the  same  way 
when  touched  by  inorganic  bodies  as  when  touched  by 
organic  bodies.  And  bearing  in  mind  that  to  creatures 
living  in  water,  the  inorganic  or  innutritive  matters  are, 
generally  speaking,  the  insoluble,  while  the  organic  or 
nutritive  are  the  soluble;  it  may  be  inferred  that  the 
selective  power  which  they  possess  is  due,  as  above  implied, 
to  the  setting  up  of  an  assimilative  process  when  assimilable 
matter  is  brought  in  contact  with  them,  and  to  the  absence 
of  that  process  when  the  matter  presented  is  not  assimilable. 
So  that  this  selective  power,  which  is  an  incipient  sense  of 
taste,  is,  primarily,  one  aspect  of  that  integrating  action 
which  mainly  constitutes  the  life.  For  thus  interpreting 
the  facts  we  have  the  warrant  that,  even  in  its  highest 
developments,  tasting  forms  one  link  in  the  chain  of  assimi- 
lative actions.  The  mouth  is  part  of  the  alimentary  canal, 
which  secretes  digestive  fluids  and  takes  up  dissolved  sub- 
stances. The  mouth  does  both  these:  its  saliva  is  a  diges- 
tive fluid,  and  in  the  act  of  tasting,  some  of  the  dissolved 
substances  are  absorbed  through  the  mucous  membrane  of 
the  tongue  and  palate. 

Smell  has  the  same  root  with  taste,  and  remains  through- 
out closely  associated  with  it.  In  aquatic  creatures  the  two 
senses  can  be  but  degrees  of  the  same:  the  one  responding 
to  a  more  dilute  solution  of  nutritive  substance,  and  the 
other  to  a  more  concentrated  solution.  As  the  soluble 
matters  which  surround  a  fragment  of  animal  tissue  are  not 
confined  to  its  actual  surface,  but  are  diffused  in  the  sur- 
rounding water  with  an  abundance  that  decreases  as  the 
distance  increases,  it  is  obvious  that  a  greater  susceptibility 
will  render  the  fragment  perceptible  before  there  is  absolute 
contact;  and  that  so,  taste  must  pass  gradually  into  smell. 
The  intimate  connection  of  taste  with  smell,  and  of  both 
with  touch,  is  displayed  even  in  man.    The  nerves  of  both 


THE  CORRESPONDENCE  AS  EXTENDING  IN  SPACE.  309 

are  spread  out  under  a  membrane  that  is  continuous  with, 
and  but  a  slight  modification  of,  the  skin;  they  lie  under 
adjacent  parts  of  this  membrane,  near  its  junction  with  the 
skin;  the  sensations  they  give  are  so  closely  allied  that, 
knowing  the  smell  of  a  substance,  we  can  frequently  form 
an  approximately  true  judgment  of  its  taste;  and  to  both, 
the  substances  to  be  perceived  must  be  presented  in  solu- 
tion— the  sapid  must  be  either  already  dissolved,  or  dis- 
solvable by  the  saliva,  and  the  odorous  must  be  condensed 
by  the  film  of  moisture  covering  the  membrane  which 
lines  the  olfactory  chambers.  Thus,  the  difference  is 
less  between  the  modes  in  which  the  sensations  are  ulti- 
mately produced,  than  between  the  forms  under  which  the 
substances  producing  them  originally  exist — liquid  or  solid 
in  the  one  case;  gaseous  or  vapous  in  the  other.  Further, 
the  relationship  of  the  sense  of  smell  to  the  fundamental 
organic  actions,  is  directly  traceable  even  in  ourselves.  The 
nostrils  and  the  olfactory  chambers  which  open  out  of  them, 
are  simply  divergent  branches  of  the  alimentary  canal,  from 
which,  in  the  embryo,  they  are  not  separate ;  and  absorbing 
into  the  system,  as  they  do,  some  of  the  floating  particles 
given  off  by  the  food  that  is  being  eaten,  or  is  about  to  be 
eaten,  their  action,  too,  is  but  an  evanescent  form  of  nutri- 
tion. Add  to  which,  that  in  so  far  as  the  olfactory  action  is 
not  nutritive  it  is  respiratory;  and  thus,  in  a  sense,  lies 
between  the  two  primary  vital  processes. 

Again,  in  its  initial  stages  even  the  faculty  of  sight  is 
implicated  with  the  functions  of  organic  life.  The  organ- 
isms which  occupy  the  border  land  between  the  animal  and 
vegetal  kingdoms,  share  with  plants  the  ability  to  decom- 
pose carbonic  acid  under  the  influence  of  light.  Water 
containing  Protozoa  gives  off  oxygen  on  exposure  to  the 
sun's  rays.  The  link  between  the  two  great  divisions  of 
living  forms,  which  these  lowest  creatures  present  in  struc- 
ture, development,  and  chemical  character,  they  appear  to 
present  in  their  nutritive  action  also.    Naturally,  then,  we 


310  GENERAL  SYNTHESIS. 

may  expect  that  on  passing  from  them  to  vegetal  and  animal 
organisms  respectively,  we  shall  on  the  one  hand  find  the 
ability  to  decompose  carbonic  acid  by  the  agency  of  light 
more  and  more  developed,  and  on  the  other  hand  more  and 
more  wanting.  Recently  disclosed  facts  answer  to  the  ex- 
pectation. In  the  first  place,  the  researches  of  Schultze  go 
to  establish  an  identity  between  the  chlorophyll  of  plants, 
and  the  colouring  matter  of  sundry  low  types  of  animals,  as 
for  instance  the  Hydra.  In  the  second  place,  the  Hydra 
habitually  shuns  the  light — habitually  chooses  the  dark  side 
of  the  vessel  in  which  it  is  placed.  May  we  not  infer  that 
the  sensitiveness  to  light  which  the  Hydra  exhibits,  results 
from  the  action  of  light  on  its  contained  chlorophyll ;  that  as 
in  plants,  this  action  is  one  through  which  the  components  of 
chlorophyll  are  assimilated ;  and  that  thus,  the  power  which 
the  primordial  tissue  possesses  to  distinguish  light  from  dark- 
ness— a  power  which  forms  the  germ  of  the  visual  faculty 
— is  due  to  a  modification  produced  by  light  on  the  general 
vital  processes?  Any  doubt  that  may  be  felt  respecting 
this  hypothesis,  will,  I  think,  disappear  on  remembering 
that  even  in  ourselves  the  general  surface  -of  the  body 
retains  a  physiological  sensitiveness  to  light.  The  darken- 
ing of  the  skin  caused  by  long  exposure  to  sunshine,  implies 
a  modified  assimilation  in  the  tissue  penetrated  by  light — a 
change  in  the  absorption  of  materials  supplied  by  the  blood. 
In  transparent  and  semi-transparent  creatures,  any  such 
photogenic  effect  must  pervade  the  whole  body;  and  if  so 
it  is  easy  to  understand  how  light  may  produce  marked 
changes  in  such  creatures. 

That  hearing  has,  like  the  other  senses,  a  root  in  the 
primitive  vital  functions,  there  is  little  if  any  direct  evidence. 
But  for  suspecting  that  it,  too,  is  differentiated  from  them, 
we  have  the  reason  that  to  sound,  as  to  light,  the  whole 
animal  organism  in  its  simplest  forms  possesses  a  feeble 
susceptibility.  A  slight  tap,  causing  a  vibration  to  pass 
through  the  vessel  containing  them,  is  responded  to  by 


THE  CORRESPONDENCE  AS  EXTENDING  IN  SPACE.  311 

creatures  in  wliom  no  sign  of  an  auditory  organ  exists. 
And  if  we  call  to  mind  the  facts  tliat  congenitally  deaf 
persons  are  acutely  affected  by  sonorous  vibrations  in  the 
bodies  they  touch,  and  can  perceive  such  vibrations  even  in 
the  air  when  produced  by  loud  concussions,  as  the  firing  of 
cannon — if  we  infer,  as  we  must,  that  even  in  man  the 
whole  body  is  in  some  degree  sensitive  to  sound,  and  that 
the  extreme  sensitiveness  of  one  part  is  simply  a  specializa- 
tion of  this  general  sensitiveness ;  we  shall  have  no  difficulty 
in  understanding  how  the  humblest  zoophytes  and  mollus- 
coid  animals  feel  the  jar  of  those  rapid  undulations  which 
constitute  objective  sound.  Of  lax  tissue,  and  of  like 
specific  gravity  with  its  medium,  one  of  these  creatures 
must  be  permeated  by  such  undulations  throughout  its 
entire  mass,  almost  as  though  it  were  so  much  water;  and 
can  scarcely  fail  to  have  the  substance  of  its  tissues  so  dis- 
turbed as  to  produce  a  marked  change  in  their  general 
state,  and  some  consequent  change  in  the  external  mani- 
festations. Still  it  may  be  asked — How  do  these  facts  and 
inferences  affiliate  the  faculty  of  hearing  on  the  primary 
vital  processes?  I  reply — They  tend  to  do  this  by  suggest- 
ing that  the  contraction  produced  by  any  sonorous  vibration 
permeating  a  zoophyte's  body,  results  from  some  modifica- 
tion of  these  vital  processes.  The  life  of  one  of  these 
creatures  is  little  else  than  the  cumulative  result  of  the  lives 
of  its  component  cells  or  nucleated  portions  of  protoplasm, 
which  severally  absorb  the  nutrient  juices  percolating  among 
them,  are  severally  bathed  by  the  oxygenating  medium,  and 
severally  carry  on  the  integrating  and  disintegrating  actions 
by  and  for  themselves.  I^ow  anything  which  causes  a 
sudden  agitation  of  the  aerating  liquid  diffused  through 
this  almost  homogeneous  tissue,  will  produce  a  sudden 
increase  of  vital  activity  in  all  the  components  of  the  tissue. 
A  rapid  succession  of  undulations  propagated  through  it 
must  do  this.  And  we  have  but  to  suppose  that  the  in- 
creased vital  activity  of  each  component  is  accompanied  by 


312  GENERAL  SYNTHESIS. 

some  change,  probably  isomeric,  which  alters  its  form,  to 
understand  how  a  contraction  of  the  entire  creature  may 
result. 

Thus,  there  is  not  a  little  reason  to  think  that  all  forms  of 
sensibility  to  external  stimuli,  are,  in  their  nascent  shapes, 
nothing  but  the  modifications  which  those  stimuli  produce 
in  that  duplex  process  of  integration  and  disintegration 
which  constitutes  the  primordial  life,  physiologically  con- 
sidered. A  zoophyte  cannot  be  touched  without  the  fluids 
diffused  throughout  the  disturbed  tissues  being  put  in 
motion,  and  so  made  to  supply  oxygen  and  nutriment  with 
greater  rapidity.  Nutritive  matter  brought  in  contact  with 
the  surface,  which  is  everywhere  absorbent,  must  excite  the 
vital  actions  still  more;  and  so  must  cause  the  touch  of 
nutritive  matter  to  be  specially  responded  to.  A  diffusion 
of  such  matter  in  the  form  of  an  odour,  will  tend  in  a 
slight  degree  to  produce  analogous  effects.  The  tissue 
having  the  requisite  chemical  nature,  light,  also,  must 
modify  the  assimilative  actions.  And,  as  just  shown, 
sonorous  vibrations  probably  do  the  like.  If  we  make  the 
reasonable  assumption  that  the  protoplasm  of  these  almost 
unorganized  creatures  is  isomerically  changed  by  changes 
in  their  vital  activity,  we  have  an  adequate  explanation  of 
the  effects  which  outer  agencies  produce.  So  far  as  they 
go,  facts  harmonize  with  the  deduction  from  the  law  of 
organic  development — the  deduction  that  as  the  primitive 
tissue  out  of  which  are  evolved  the  organs  of  vegetative  life, 
possesses,  to  some  extent,  the  functional  powers  of  those 
organs;  so  must  it,  to  some  extent,  possess  the  functional 
powers  of  the  organs  of  animal  life,  and  among  them  of  the 
senses,  which  similarly  arise  out  of  it  by  a  continuous  differ- 
entiation and  integration. 

Closing  here  these  speculations  respecting  the  genesis  of 
the  several  faculties  through  which  the  animal  organism 
holds  communication  with  the  external  world,  let  us  now  go 
on  to  our  immediate  subject — that  extension  of  the  corre- 


THE   CORRESPONDENCE  AS  EXTENDING  IN  SPACE.  313 

spondence  in  Space,  which  accompanies  the  evolution  of 
these  faculties. 

§  141.  Differentiated  gradually,  as,  in  aquatic  creatures, 
smell  is  from  touch  and  taste,  its  nascent  form  is  not  likely 
to  be  detected  without  careful  experiments ;  and  I  have  not 
met  with  accounts  of  such.  "  How  far  any  sense  of  smell 
exists  in  the  lower  invertebrata,  cannot  be  satisfactorily  de- 
termined," says  Dr.  Carpenter:  "  but  it  would  seem  not  im- 
probable that  even  where  no  special  organ  is  apparent,  some 
part  of  the  general  surface  may  be  endowed  with  olfactive 
sensibility."  But  however  the  sense  of  smell  originates,  we 
may  conclude  that  only  when  in  some  degree  localized,  does 
it  become  a  means  whereby  internal  relations  can  be  brought 
into  something  like  definite  correspondence  with  external 
relations  which  do  not  occur  in  contact  with  the  body. 
Supposing,  for  argument's  sake,  that  along  with  its  other 
diffused  faculties  the  whole  mass  of  the  primitive  animal 
possesses  a  feeble  susceptibility  to  odours;  the  only  corre- 
spondence which  may  be  established  through  this,  must  be 
seen  in  some  state  of  readiness  to  seize  the  prey,  or  avoid 
the  enemy,  whose  proximity  an  odour  implies.  Though,  by 
means  of  such  endowment,  an  inner  relation  can  be  adjusted 
to  an  outer  relation  a  little  removed  from  the  surface ;  yet, 
there  can  be  no  adjustment  to  relations  either  of  direction 
in  space  or  of  distance  in  space.  But  as  soon  as  there  exists 
a  susceptibility  that  is  somewhat  localized,  the  organism 
must  be  differently  affected  by  an  odoriferous  body,  accord- 
ing as  it  is  situated  in  this  or  that  position.  And  when,  as 
an  accompaniment  of  specialization,  there  is  increased  effi- 
ciency, a  feebly-scented  object  near  to  the  more  highly 
sensitive  tract,  may  produce  a  response  as  great  as  a 
strongly-scented  object  somewhere  in  its  neighbourhood 
produces  in  an  organism  possessed  of  a  diffused  but  inferior 
susceptibility. 

Passing  from  these  vague  beginnings,  it  will  be  obvious 


514  GENERAL  SYNTHESIS. 

that  as  fast  as  there  is  developed  at  the  entrance  of  the 
respiratory  passages  a  definite  apparatus  capable  of  being 
excited  by  floating  particles,  there  must  be  an  extension  of 
the  space  through  which  co-existences  and  sequences  in  the 
environment  can  establish  corresponding  co-existences  and 
sequences  in  the  organism.  When  we  trace  up  the  evolu- 
tion of  the  faculty  to  that  perfection  in  which  it  is  possessed 
by  dogs  and  by  deer,  we  see  that  one  of  the  aspects  under 
which  the  advance  presents  itself,  is  the  increasing  distance 
at  which  certain  inner  and  outer  relations  can  be  brought 
into  adjustment;  and  that,  other  things  equal,  there  is  a 
simultaneous  advance  in  the  degree  of  life. 

§  142.  Though  that  ability  to  distinguish  light  from  dark- 
ness which  characterizes  the  entire  body  in  sundry  of  the 
humblest  types,  foreshadows  the  visual  faculty,  nothing  like 
what  we  call  sight  results  until  this  ability  is  concentrated 
in  a  particular  spot.  The  rudimentary  eye  consisting,  as 
in  a,  Plcmaria,  of  some  pigment  grains,  may  be  considered 
as  simply  a  part  of  the  surface  more  irritable  by  light  than 
the  rest.  Some  idea  of  the  impression  it  is  fitted  to  receive 
may  be  formed  by  turning  our  closed  eyes  towards  the  light, 
and  passing  the  hand  backwards  and  forwards  before  them. 
But  as  soon  as  even  this  slight  specialization  of  function  is 
reached,  it  becomes  possible  for  the  organism  to  respond  to 
the  motions  of  opaque  bodies  that  pass  near.  While  only  a 
general  sensitiveness  to  light  exists,  the  intercepting  of  the 
sun's  rays  by  something  which  throws  the  whole  or  a  greater 
part  of  the  creature  into  shade,  is  required  to  produce  an 
internal  change;  but  when  there  comes  to  be  a  specially 
sensitive  spot,  anything  which  casts  a  shadow  on  that  spot 
alone,  produces  an  internal  change.  And  as  that  which 
obscures  only  a  small  part  of  the  organism  is  usually  a 
comparatively  small  object,  this  advance  from  diffused  sen- 
sitiveness to  concentrated  sensitiveness  enables  the  organism 
to  respond,  not  only  to  marked  general  changes  in  luminous- 


THE  CORRESPONDENCE  AS  EXTENDING  IN  SPACE.  315 

ness  which  its  environment  undergoes,  but  also  to  marked 
special  changes  in  luminousness  caused  by  the  motions  of 
adjacent  bodies. 

The  contrast  between  light  and  darkness,  or  rather  be- 
tween widely  different  degrees  of  light,  being  all  that  the 
most  rudimentary  vision  recognizes;  and  distinct  obscura- 
tion being  producible  by  an  adjacent  small  object  only  when 
it  is  very  close;  we  may  infer  that  nascent  vision  extends 
to  those  objects  alone  which  are  just  about  to  touch  the 
organism,  either  in  consequence  of  their  motion  or  of  its 
motion.  We  may  infer  that  it  amounts  at  first  to  little 
more  than  anticipatory  touch;  and  that  so  there  is  estab- 
lished in  the  organism  a  general  relation  between  visual  and 
tactual  impressions,  corresponding  to  the  general  relation 
between  opacity  and  solidity  in  the  environment.  Be  this 
as  it  may,  however,  it  is  clear  that  an  incipient  faculty  of 
sight,  though  the  vaguest  imaginable  in  the  sensations  it 
gives,  and  the  most  limited  that  can  be  conceived  in  range, 
implies  not  only  some  extension  of  the  correspondence  in 
space,  but  a  new  order  of  correspondence. 

As  we  ascend  to  creatures  having  more  developed  eyes, 
we  find  an  increase  in  the  sphere  of  surrounding  space 
throughout  which  external  relations  can  establish  correspond- 
ing internal  relations.  A  slight  convexity  of  the  epidermic 
layer  lying  over  the  sensitive  tract,  first  serves,  by  concen- 
trating the  rays,  to  render  appreciable  less  marked  varia- 
tions in  the  quantity  of  light;  and  thus  brings  into  view 
the  same  bodies  at  a  greater  distance,  and  smaller  or  less 
opaque  bodies  at  the  same  distance.  From  this  point  up- 
wards, through  the  various  types  of  aquatic  creatures  to  the 
higher  air-breathing  creatures,  we  trace,  under  various 
forms  and  modifications,  a  complicating  visual  apparatus 
and  a  widening  space  through  which  the  correspondence 
extends.  It  is  needless  to  go  into  details.  Hypotheses  and 
illustrations  aside,  it  is  obvious  that  from  the  polype  which 
does  not  stir  till  touched,  up  to  the  telescopic-eyed  vulture 


316  GENERAL  SYNTHESIS. 

or  the  far-sighted  Bushman,  one  aspect  of  progressing  life 
is  the  greater  and  greater  remoteness  at  which  visible  rela- 
tions in  the  environment  produce  adapted  relations  in  the 
organism. 

§  143.  Similarly  with  the  auditory  faculty.  So  long  as 
the  susceptibility  to  sonorous  vibrations  is  slight,  and  pos- 
sessed by  the  body  at  large,  there  is  nothing  like  what  we 
call  hearing.  Only  when  the  susceptibility  comes  to  be  in- 
tensified in  one  place,  can  a  sound  proceeding  from  a  par- 
ticular point  in  the  environment,  be  distinguished  from  a 
tremor  of  the  environment  as  a  whole.  After  there  has 
arisen  a  rudimentary  ear,  consisting  of  a  dermal  sac  con- 
taining otolithes,  which  multiply  the  vibrations  striking  the 
skin  that  covers  them  as  the  primitive  cornea  concentrates 
the  rays  passing  through  it;  then,  a  moderate  sound  at 
some  distance  or  a  slight  sound  close  to  it,  may  produce 
on  the  creature  as  great  an  effect  as  the  violent  shock  of 
its  entire  medium  produces  on  a  creature  not  thus  endowed. 
And  along  with  this  new  sense  there  comes  into  existence 
a  new  set  of  correspondences — those  between  certain  audi- 
tory impressions  and  consequent  motions  in  the  organism, 
and  certain  sound-causing  powers  and  co-existent  properties 
in  adjacent  bodies. 

Successive  improvements  of  this  faculty,  as  of  those 
already  dealt  with,  expand  the  surrounding  sphere  through- 
out which  certain  relations  in  the  environment  cause  adapted 
relations  in  the  organism.  It  cannot  be  denied  that  though 
the  minor  irregularities  involved  by  their  special  habits  are 
considerable,  yet,  viewed  in  the  mass,  animals  of  higher 
and  higher  types  show  us  greater  and  greater  ranges  in 
their  auditory  correspondences. 

§  144.  The  extension  of  the  correspondence  in  space 
does  not  end  with  the  perfecting  of  the  senses.  In  crea- 
tures of  comparatively-advanced  organization,  there  arise 


THE  CORRESPONDENCE  AS  EXTENDING  IN  SPACE.  317 

powers  of  adjusting  inner  relations  to  outer  relations  that 
are  far  too  remote  for  direct  perception.  The  motions  by 
which  a  carrier-pigeon  finds  its  way  home  though  taken  a 
hundred  miles  away,  cannot  be  guided  by  sight,  smell,  or 
hearing,  in  their  direct  and  simple  forms.  Chased  animals 
that  make  their  way  across  the  country  to  places  of  refuge 
out  of  view,  are  obviously  led  by  combinations  of  past  and 
present  impressions  which  enable  them  to  transcend  the 
sphere  of  the  senses.  And  thus  also  it  must  be  with  crea- 
tures that  annually  migrate  to  other  lands. 

In  man,  this  secondary  process  of  extension  is  carried 
still  further.  Though  the  correspondences  he  effects  by 
immediate  perception  have  a  narrower  range  in  space  than 
those  of  some  inferior  creatures ;  and  though  in  that  species 
of  indirect  adjustment  just  exemplified,  he  is  behind  sundry 
wild  and  domestic  animals;  yet,  by  still  more  indirect 
means,  he  adjusts  internal  relations  to  external  relations  that 
are  immensely  beyond  the  appreciation  of  lower  beings. 
By  combining  his  own  perceptions  with  the  perceptions  of 
others  as  registered  in  maps,  he  can  reach  special  places 
lying  thousands  of  miles  away  over  the  Earth's  surface.  A 
ship,  guided  by  compass,  and  stars,  and  chronometer,  brings 
him  from  the  antipodes  information  by  which  his  purchases 
here  are  adapted  to  prices  there.  From  the  characters 
of  exposed  strata  he  infers  the  presence  of  coal  below; 
and  thereupon  adjusts  the  sequences  of  his  actions  to  co- 
existences a  thousand  feet  underneath.  Nor  is  the  environ- 
ment through  which  his  correspondences  reach,  limited  to 
the  surface  and  the  substance  of  the  Earth.  It  stretches 
into  the  surrounding  sphere  of  infinity.  It  was  extended  to 
the  moon  when  the  Chaldeans  discovered  how  to  predict 
eclipses;  to  the  sun  and  nearer  planets  when  the  Coperni- 
can  system  was  established;  to  the  remoter  planets  when 
an  improved  telescope  disclosed  one,  and  calculation  fixed 
the  position  of  the  other;  to  the  stars  when  their  parallax 
and  proper  motion  were  measured;  and,  in  a  vague  way, 


818  GENERAL  SYNTHESIS. 

even  to  the  nebulae,  when  their  composition  and  fonns  of 
structure  were  ascertained. 

§  145.  Before  leaving  this  general  proposition,  that  the 
progress  of  life  and  intelligence  is,  under  one  of  its  aspects, 
an  extension  of  the  space  through  which  the  correspondence 
between  the  organism  and  its  environment  reaches,  it  may 
be  well  to  remark  that  its  truth  is  independent  of  all  con- 
clusions as  to  the  modes  in  which  the  correspondence  is 
developed.  In  the  earlier  part  of  the  chapter  I  have  filled 
up  some  of  the  gaps  in  our  knowledge  by  reasonings  that 
are  partially  hypothetical;  and  have  thus  opened  the  door 
to  possible  criticisms,  which  may  at  first  sight  be  supposed 
to  tell  against  the  doctrine  at  large.  But  a  moment's  con- 
sideration will  show  that  by  whatever  steps  the  senses  of 
smell,  sight,  and  hearing,  arise,  the  result  remains  the  same. 
Unquestionable  facts  form  the  substance  of  the  argument. 
It  is  a  fact  that  where  the  sense  of  touch  is  the  only  one 
definitely  manifested,  the  correspondence  between  the  or- 
ganism and  its  environment  extends  only  to  that  part  of 
the  environment  by  which  the  organism  is  bathed.  It  is  a 
fact  that  the  appearance  of  the  higher  senses,  even  in  their 
most  rudimentary  forms,  is  accompanied  by  some  extension 
of  the  space  throughout  which  correspondences  can  be 
effected.  It  is  a  fact  that  the  successive  stages  in  the 
development  of  each  sense  imply  successive  enlargements 
of  this  sphere  of  space.  And  it  is  a  fact  that  the  advent  of 
rationality  is,  among  other  ways,  shown  in  the  carrying  of 
these  enlargements  still  further. 

Here,  indeed,  let  me  draw  attention  to  the  truth  indi- 
cated by  some  of  the  above  examples,  that  the  extension 
of  the  correspondence  in  space  is  exhibited  not  in  the  as- 
cending grades  of  animal  life  alone,  but  in  the  successive 
phases  of  human  civilization,  and  is  even  now  going  on. 
From  early  races  acquainted  only  with  neighbouring  locali- 
ties, up  to  modem  geographers  who  specify  the  latitude  and 


THE  CORRESPONDENCE  AS  EXTENDING  IN  SPACE,  319 

longitude  of  every  place  on  the  globe — from  tlie  ancient 
builders  and  metallurgists,  knowing  but  surface-deposits, 
up  to  the  geologists  of  our  day  whose  data  in  some  cases 
enable  them  to  describe  the  material  existing  at  a  depth 
never  yet  reached  by  the  miner — from  the  savage  barely 
able  to  say  in  how  many  days  a  full  moon  will  return,  up  to 
the  astronomer  who  ascertains  the  period  of  revolution  of  a 
double  star — there  has  been  a  gradual  widening  of  the  sur- 
rounding region  throughout  which  the  adjustment  of  inner 
to  outer  relations  extends. 

It  remains  only  to  point  out  the  additional  evidence 
thus  afforded  that  the  degree  of  life  varies  as  the 
degree  of  correspondence.  On  the  one  hand,  each  further 
extension  of  the  correspondence  in  space  adds  to  the 
number  of  external  relations  to  which  internal  relations  are 
adjusted — adds,  that  is,  to  the  number  of  internal  changes 
— adds  therefore  to  the  amount  of  life.  On  the  other  hand, 
the  greater  the  space  throughout  which  the  correspondence 
reaches,  and  the  more  numerous  the  adjustments  which  can 
consequently  be  made,  the  greater  must  be  the  number  of 
cases  in  which  food  is  obtained  and  danger  shunned. 
Whence  we  may  clearly  see  how  life  and  ability  to  maintain 
life,  are  two  sides  of  the  same  fact — how  life  is  a  combina- 
tion of  processes  the  result  of  whose  workings  is  their  ov/n 
continuance. 


CHAPTER  y. 

THE    COEEESPONDENCE    AS    EXTENDING    IN    TIME. 

§  146.  It  was  pointed  out  some  pages  back  (§  136),  that 
while  the  lowest  Protophyta  and  Protoza  display  no  mani- 
fest adjustments  of  internal  changes  to  changes  in  the  envi- 
ronment, the  higher  plants  pass  through  cycles  or  states  an- 
swering to  the  cycles  of  the  seasons.  Whether  this  should  be 
regarded  as  a  progress  towards  correspondence  in  Time,  is 
doubtful.  It  may  be  said  that  since  in  a  tree  the  budding, 
blossoming,  ripening  the  fruit,  and  dropping  the  leaves, 
occur  at  the  same  times  with  fit  external  conditions,  the 
inner  sequences  are  conformed  to  the  outer  ones.  But  it 
may  be  replied  that  this  is  an  incidental  result  of  the  per- 
petual adaptation  of  the  internal  actions  to  external  co- 
existences (temperature,  light,  moisture),  which,  by  passing 
through  a  series  of  variations,  involve  a  parallel  series  of 
variations  in  the  plant.  It  may  be  argued  that  the  putting 
forth  of  leaves  has  reference  simply  to  the  then  concurring 
influences,  and  has  no  direct  reference  to  the  subsequent  nu- 
trition of  the  fruit;  that  the  true  nature  of  these  vegetative 
changes  is  seen  in  the  fact  that  a  tree  will  flower  in  the 
autumn  if  the  heat  be  great  enough;  and  that  thus  plant- 
life  exhibits  no  true  correspondence  to  sequences  in  the 
environment,  but  only  to  co-existences  in  it.  To  decide  be- 
tween these  views  is  not  easy;    though  on  the  whole  the 

last  seems  the  more  rational.    But  at  any  rate,  this  species 

820 


THE  CORRESPONDENCE  AS  EXTENDING  IN  TIME.    321 

of  correspondence  in  Time,  if  such  it  be,  is  of  a  vague 
kind  compared  with  that  properly  so  called. 

Turning  to  those  more  definite  cases  which  animal  life 
displays,  it  is  to  be  observed  that  in  creatures  possessing  no 
other  sense  than  that  of  touch,  the  sole  external  relations 
with  which  internal  relations  can  be  put  in  correspondence, 
are  relations  of  co-existence.  Only  when  there  comes  to  be 
some  amount  of  smell,  or  sight,  or  hearing,  can  sequences 
in  the  environment  be  met  by  adjusted  sequences  in  the 
organism.  The  connexion  between  the  tangibility  of  an 
adjacent  body  and  some  co-existent  property  possessed  by 
it,  is  the  only  one  to  which,  in  a  zoophyte,  the  connexion 
between  irritation  and  contraction  answers.  Time  is  no 
more  involved  than  Space.  But  when  relations  among 
things  or  attributes  that  are  in  any  degree  removed  from 
the  organism,  become  cognizable — when,  for  example,  there 
exists  incipient  vision,  and  obstruction  of  light  is  often 
followed  by  a  touch  from  the  obstructing  body — then,  an 
organic  response  to  an  external  sequence  becomes  possible: 
then  the  organism  can  move  in  anticipation  of  motion 
in  an  external  body.  Two  phenomena  in  the  environ- 
ment, the  one  immediately  succeeeding  the  other,  pro- 
duce two  phenomena  in  the  organism  in  like  succes- 
sion. 

Or,  to  present  the  proposition  under  another  aspect: — As 
the  simplest  sequences,  and  those  first  perceived,  are  me- 
chanical sequences;  as  mechanical  sequences  imply  change 
of  position ;  as  change  of  position  implies  progress  through 
Space;  it  follows  that  only  when  there  is  some  degree  of 
space-penetrating  faculty,  can  there  be  any  adaptation  in 
the  organism  to  changes  of  position  in  adjacent  objects — 
any  adjustment  to  external  sequences — any  correspondence 
in  Time.  After  the  ability  to  respond  to  the  touches  of 
surrounding  bodies,  the  next  advance  is  the  ability  to  re- 
spond to  those  motions  of  them  which  precede  touch;  and 
since  motion  involves  both  Time  and  Space,  the  first  exten- 


322  GENERAL  SYNTHESIS. 

sion  of  the  correspondence  in  Time  is  necessarily  coeval 
with  its  first  extension  in  Space. 

§  147.  Throughout  the  successive  stages  in  the  develop- 
ment of  the  senses,  these  two  orders  of  correspondence 
progress  together.  In  proportion  as  the  distance  at  which  a 
moving  object  is  perceivable  increases,  the  greater  becomes 
the  duration  of  the  external  actions,  or  chains  of  actions,  to 
which  the  internal  changes  may  be  adjusted.  Other  things 
equal,  the  more  remote  any  body,  the  longer  must  be  the 
interval  before  it  can  act  on  the  organism  or  the  organism 
on  it;  that  is — the  longer  must  be  the  time  between  the 
outer  antecedents  and  consequents  with  which  the  inner 
antecedents  and  consequents  are  put  in  correspondence. 
The  inner  and  outer  sequences  shown  in  the  pursuit  of  a 
heron  by  a  hawk,  are  longer  than  those  shown  in  the  pur- 
suit of  a  fish  by  a  heron;  and  are  so  chiefly  because  the 
vision  of  a  heron  is  wider  than  that  of  a  fish.  Without 
giving  cases,  it  will  be  manifest  that  by  the  development  of 
smell  and  hearing  also,  the  correspondences  are  simultane- 
ously extended  in  duration  and  distance.  Not  that  they 
maintain  a  constant  ratio.  The  connexion  between  them  is 
variously  modified  by  circumstances.  The  character  of  the 
environment,  the  particular  powers  of  the  organism  in 
respect  of  locomotion,  as  well  as  other  conditions,  greatly 
affect  it.  All  that  can  be  said  is,  that  the  two  kinds  of 
extension  are  connate;  and  that,  in  so  far  as  mechanical 
phenomena  are  concerned,  they  display  throughout  a  gen- 
eral inter-dependence. 

§  148.  This  limitation — "  in  so  far  as  mechanical  pheno- 
mena are  concerned  " — serves  to  introduce  the  fact  that,  in 
respect  to  other  orders  of  phenomena,  the  progress  of  the 
correspondence  in  Time  has  little  or  nothing  to  do  with  its 
progress  in  Space.  Did  all  actions  involve  perceptible 
motion — were  alteration  of  position  a  necessary  accompani- 


THE  CORRESPONDENCE  AS  EXTENDING  IN  TIME.    323 

ment  of  every  alteration,  the  two  would  be  uniformly  re- 
lated. But  as  there  are  hosts  of  changes,  chemical,  thermal, 
electric,  vital,  which  involve  no  appreciable  mechanical 
change — as  there  are  numberless  changes  of  state  which 
occur  without  changes  of  place ;  it  results  that,  in  the  growth 
of  internal  adjustments  to  these,  there  is  an  extension  of  the 
correspondence  in  Time  separate  from,  and  additional  to, 
that  which  arises  from  its  extension  in  Space. 

This  second  species  of  correspondence  in  Time  is  of  a 
much  higher  order — is,  in  fact,  a  far  more  extended  corre- 
spondence. For  the  ordinary  mechanical  sequences  in 
surrounding  bodies  by  which  each  organism  is  affected,  are 
incalculably  more  rapid  than  the  non-mechanical  sequences. 
The  motions  of  enemies  or  of  prey,  even  when  sluggish,  are 
readily  appreciable :  a  few  seconds  only,  at  most,  are  needed 
to  bring  about  manifest  changes.  But  the  decay  of  a  dead 
animal,  or  the  ripening  of  fruit,  or  the  drying  up  of  a  pool, 
or  the  hatching  of  an  egg,  occupies  an  immensely  longer 
interval.  One  of  these  latter  sequences'  has  a  duration  a 
hundred,  a  thousand,  a  million  times  as  great  as  one  of  the 
former;  and  the  ability  of  the  organism  to  adjust  itself  to 
them,  implies  a  proportionate  extension  of  the  correspon- 
dence in  Time. 

Hence  the  fact  that  only  when  we  come  to  creatures  of 
comparatively  high  intelligence,  do  we  meet  with  inner 
changes  in  adaptation  to  outer  changes  of  a  non-mechanical 
kind.  For  we  must  not  class  as  coming  under  this  head 
such  actions  of  inferior  animals  as  are  adjusted  to  daily 
and  annual  modifications  of  the  environment.  These,  like 
parallel  actions  in  plants,  are  most  likely  nothing  but  the 
cumulative  results  of  successive  adaptations  of  the  organism 
to  successive  co-existences  in  the  environment.  It  is  ana- 
tomically demonstrable  that  the  pairing  and  nidification  of 
birds  in  the  spring,  is  preceded  by  constitutional  changes 
which  are  probably  produced  by  more  food  and  higher  tem- 
perature. And  it  is  a  rational  inference  that  the  whole 
23 


324  GENERAL  SYNTHESIS. 

series  of  processes  implied  in  the  rearing  of  a  brood,  are 
severally  gone  through,  not  with  any  recognition  of  remote 
ends,  but  solely  under  the  stimulus  of  conditions  continu- 
ously present. 

An  early  stage  of  the  higher  kind  of  correspondence  in 
Time,  must  be  looked  for  where  the  period  between  ante^ 
cedent  and  consequent  is  but  a  few  hours.  Birds  that  fly 
from  inland  to  the  sea-side  to  feed  when  the  tide  is  out,  and 
cattle  that  return  to  the  farm-yard  at  milking-time,  supply 
instances.  Even  here,  however,  there  is  not  a  purely  intel' 
ligent  adjustment  of  inner  to  outer  sequences;  for  creatures 
accustomed  to  eat  or  to  be  milked  at  regular  intervals, 
come  to  have  adapted  recurrences  of  constitutional  states, 
and  the  sensations  accompanying  these  states  form  the 
proximate  stimuli  to  their  acts.  Nevertheless,  we  must 
not  wholly  exclude  these  instances  from  the  category 
of  advancing  correspondence  in  Time;  but  must  recognize 
them  as  imperfect  and  transitional  forms  of  it,  through 
which  only  the  higher  forms  can  be  reached.  For  if  we 
consider  under  what  conditions  only  an  inner  sequence  can 
be  adjusted  to  some  outer  sequence  occupying  hours  or 
days,  it  becomes  plain  that  there  must  exist  in  the  organ- 
ism a  means  of  recognizing  duration.  Unless  the  organism 
is  differently  affected  by  periods  of  different  lengths,  its 
actions  cannot  be  made  to  fit  slow  external  actions.  "When 
we  pass  from  those  mechanical  sequences  in  which  the 
motion  of  the  external  body  itself  serves  the  organism  as  a 
measure  of  duration,  to  those  non-mechanical  sequences 
which  not  only  afford  no  measure  but  last  incomparably 
longer,  the  only  measure  of  duration  available  is  one 
resulting  from  the  periodic  sensations  of  the  organism 
itself.  Naturally,  then,  these  first  examples  of  the  higher 
correspondence  in  Time,  arise  where  an  internal  periodicity 
agrees  with  an  external  periodicity.  And  naturally,  in  the 
cases  next  above  these — cases  implying  some  foresight  of 
future  events,  such  as  is  shown  by  a  dog  hiding  a  bone  in 


THE  CORRESPONDENCE  AS  EXTENDING  IN  TIME.    325 

anticipation  of  the  time  when  he  will  be  again  hungry — 
there  is  a  distinct  reference  to  this  same  recurrence  of 
organic  states. 

§  149.  The  existence  of  so  wide  a  gap  between  ordinary 
mechanical  sequences  and  most  non-mechanical  sequences, 
in  respect  of  the  periods  they  occupy,  joined  with  the  cir- 
cumstance that  the  adjustment  of  internal  sequences  to 
lengthened  external  sequences  implies  estimation  of  inter- 
vals, explains  how  it  happens  that  only  when  we  reach  an 
advanced  phase  of  intelligence,  does  this  higher  kind  of 
correspondence  in  Time  begin  to  exhibit  a  marked  exten- 
sion. Not  that  the  transition  is  sudden.  During  the  first 
stages  of  human  progress,  the  method  of  estimating  epochs 
does  not  differ  in  nature  from  that  employed  by  the  more 
intelligent  animals.  There  are  historical  traces  of  the  fact 
that,  originally,  the  civilized  races  adjusted  their  actions  to 
the  longer  sequences  in  the  environment  just  as  Australians 
and  Bushmen  do  now,  by  observing  their  coincidence  with 
the  migrations  of  birds,  the  floodings  of  rivers,  the  flower- 
ings of  plants.  And  it  is  obvious  that  the  savages  who, 
after  the  ripening  of  a  certain  berry  travel  to  the  sea-shore, 
knowing  that  they  will  then  find  a  particular  shell-fish  in 
season,  are  guided  by  much  the  same  process  as  the  dog 
who,  on  seeing  the  cloth  laid  for  dinner,  goes  to  the 
window  to  watch  for  his  master.  But  when  these  pheno- 
mena of  the  seasons  are  observed  to  coincide  with  recurring 
phenomena  in  the  heavens — when,  as  was  the  case  with  the 
aboriginal  Hottentots,  periods  come  to  be  measured  partly 
by  astronomical  and  partly  by  terrestrial  changes;  then  we 
see  making  its  appearance  a  means  whereby  the  corre- 
spondence in  Time  may  be  indefinitely  extended.  The 
sun's  daily  movements  and  the  monthly  phases  of  the  moon 
having  once  been  generalized,  and  some  small  power  of 
counting  having  been  reached,  it  becomes  possible  to  recog- 
nize the  intervals  between  antecedents  and  consequents 


326  GENERAL  SYNTHESIS. 

that  are  long  apart,  and  to  adjust  the  actions  to  them. 
Multitudes  of  sequences  in  the  environment  which,  in  the 
absence  of  answering  functional  periods,  cannot  be  directly 
responded  to  by  the  organism,  may  be  discerned  and  in- 
directly responded  to  when  there  arises  this  ability  of 
numbering  days  and  lunations.  Given  a  unit  of  Time  and  a 
faculty  of  registering  units,  and  the  internal  actions  may 
be  adjusted  to  countless  non-mechanical  actions  going  on 
externally,  which,  though  the  least  conspicuous,  are  often 
the  most  potent  in  their  effects. 

This  higher  order  of  correspondence  in  Time,  scarcely 
more  than  foreshadowed  among  the  higher  animals,  and 
definitely  exhibited  only  when  we  arrive  at  the  human 
race,  has  made  marked  progress  during  civilization.  The 
lowest  tribes  of  men  who  wander  from  place  to  place  as  the 
varying  supplies  of  wild  animals,  roots,  and  insects,  dictate, 
do  not  adapt  their  conduct  to  periods  exceeding  a  year  in 
duration.  Hardly  worthy  to  be  defined  as  creatures  "  look- 
ing before  and  after,"  their  actions  respond  to  few  if  any  se- 
quences longer  than  those  of  the  conspicuous  and  often-re- 
curring phenomena  of  the  seasons.  But  among  semi-civil- 
ized races  we  see,  in  the  building  of  permanent  huts,  in  the 
breeding  and  accumulation  of  cattle,  in  the  storing  of  com- 
modities, that  longer  sequences  are  recognized  and  measures 
taken  to  meet  them.  And  when  united  in  higher  social 
states,  men  show,  by  planting  trees  that  will  not  bear  fruit 
for  a  generation,  by  the  elaborate  educations  they  give  their 
children,  by  building  houses  that  will  last  for  centuries,  by  in- 
suring their  lives,  by  struggling  for  future  wealth  or  fame, 
that  in  them,  internal  antecedents  and  consequents  are  ha- 
bitually adjusted  to  external  ones  which  are  extremely  long 
in  their  intervals.  Especially  is  this  extension  of  the 

correspondence  in  Time  displayed  by  progressing  science. 
Beginning  with  the  sequences  of  day  and  night,  men 
advanced  to  the  monthly  changes  of  the  moon,  next  to  the 
sun's  annual  cycle,  next  to  the  cycle  of  the  moon's  eclipses 


THE  CORRESPONDENCE  AS  EXTENDING  IN  TIME.    327 

and  tlie  periods  of  the  planets;  while  modern  astronomy 
determines  the  vast  interval  after  which  the  Earth's  axis 
will  again  point  to  the  same  place  in  the  heavens,  and 
the  scarcely  conceivable  epoch  after  which  planetary  pertur- 
bations repeat  themselves. 

When,  as  in  these  cases,  the  sequences  exceed  in  length  the 
lives  of  individual  men,  the  correspondence  is  effected  by  the 
agency  of  many  men  whose  actions  are  co-ordinated.  An 
astronomer  who  computes  the  elements  of  a  comet  of  brief 
period,  and  who,  after  the  lapse  of  certain  years,  months, 
and  days,  turns  his  telescope  to  that  region  of  the  heavens 
in  which  the  expected  body  shortly  makes  its  appearance, 
shows  in  himself  the  entire  correspondence  between  an 
internal  series  of  changes  and  an  external  series.  But  when 
centuries  pass  between  the  predilection  and  its  fulfilment,  we 
see  that  by  the  help  of  written  symbols,  the  proceedings  of 
successive  men  are  united  into  one  long  sequence,  dis- 
playing the  same  adjustment  to  an  external  sequence  as 
though  it  had  occurred  in  a  single  man  surviving  through- 
out the  interval.  Perhaps  nothing  more  strongly  suggests 
the  conception  of  an  embodied  Humanity,  than  this  ability 
of  Humanity  as  a  whole  to  respond  to  environing  changes 
which  are  far  too  slow  to  be  responded  to  by  its  component 
individuals. 

§  150.  The  extension  of  the  correspondence  in  Time,  like 
its  extension  in  Space,  involves  an  increased  amount  of  life 
and  renders  possible  a  greater  continuance  of  life.  Each 
longer  sequence  recognized  implies  an  adjustment  of  a  new 
set  of  internal  relations  to  a  new  set  of  external  relations — 
implies  an  additional  series  of  vital  actions — implies,  there- 
fore, an  increased  number  and  heterogeneity  of  the  com- 
bined changes  which  constitute  life.  At  the  same  time, 
the  adjustment  of  the  organism  to  these  successively  longer 
sequences,  is  itself  an  avoidance  of  dangers  or  a  seizing  of 
advantages;   and  is  consequently  a  process  of  self-preserva- 


328  GENERAL  SYNTHESIS. 

tion.  As  we  have  seen,  the  ascending  grades  of  brute  life 
illustrate  this,  and  it  is  illustrated  by  human  progression. 
The  civilized  races,  by  recognizing  slower  changes  and  pro- 
viding for  more  remote  results  than  the  hand-to-mouth- 
living  savage  does,  obviously  meet  more  numerous  contin- 
gencies and  secure  greater  longevity;  while,  in  the  meeting 
of  these  more  numerous  contingencies  a  higher  degree 
of  vital  activity  is  involved.  It  may  be  argued 

with  some  plausibility,  that  the  like  is  true  even  of  the 
adjustment  of  our  conceptions  to  those  immense  periods 
involved  in  the  larger  generalizations  of  astronomy  and 
geology.  For  little  as  the  recognition  of  these  modifies 
human  actions  directly,  yet  indirectly,  by  abolishing  old 
theories  of  creation  and  humanity,  it  ultimately  produces  a 
powerful  effect  on  the  conduct  of  the  race. 


CHAPTEE  VI. 

THE    COEEESPONDENCE    AS    INCEEASING    IN    SPECIALITY. 

§^151.  Otherwise  considered,  the  evolution  of  life  is  an 
advance  in  the  Speciality  of  the  correspondence  between 
inner  and  outer  relations.  In  part,  this  is  an  aspect  of  the 
processes  described  in  the  last  two  chapters;  and  in  part 
it  is  a  further  and  a  higher  process.  Just  as  we  saw  that 
in  so  far  as  mechanical  phenomena  are  concerned,  the  exten- 
sion of  the  correspondence  goes  on  2)0/^1  passu  in  Space  and 
in  Time,  but  that  the  extension  of  the  correspondence  in 
Time  afterwards  takes  in  many  other  orders  of  phenomena; 
so,  though  at  first  the  increase  of  the  correspondence  in 
Speciality  is  inseparable  from  its  extension  in  Space  and 
Time,  yet  it  presently  comes  to  include  innumerable  cor- 
respondences not  comprehended  under  either  of  these. 
Objectively,  the  development  of  the  correspondence  is 
essentially  one;  but  the  limitations  of  our  intellects  pre- 
vent us  from  grasping  it  as  one;  and  it  is  an  inconvenience 
accompanying  the  presentation  of  it  in  parts,  that  the 
divisions  overlap  one  another. 

The  first  specialization  of  the  correspondence  occurs  on 
passing  from  those  simplest  organisms  whose  environments 
are  homogeneous  both  in  Space  and  Time,  to  those  whose 
environments  are  homogeneous  in  Space  but  heterogeneous 
in  Time.  The  yeast-cell,  touched  on  all  sides  by  the  ele- 
ments it  requires,  and  during  its  short  life  kept  under  the 

829 


330  GENERAL  SYNTHESIS. 

needful  conditions,  exhibits  a  correspondence  in  the  highest 
degree  general.  But  the  tree  which,  though  constantly 
bathed  by  nutritive  materials,  assimilates  them  only  under 
particular  states  of  the  environment,  exhibits,  in  the  ad- 
justment of  its  internal  changes  to  the  recurring  external 
changes,  some  advance  towards  speciality  of  correspon- 
dence. 

The  next  step  of  the  same  nature — the  step  which  dis- 
tinguishes, so  far  as  it  can  be  distinguished,  the  animal 
kingdom  from  the  vegetal  one — takes  place  when,  relatively 
to  the  needs  of  the  organism,  the  environment  is  hetero- 
geneous both  in  Time  and  Space.  To  the  lowest  living 
things,  the  integrable  matter  is  everywhere  present  upder 
uniformly  available  conditions.  To  plants  in  general,  it  is 
everywhere  present,  but  not  under  uniformly  available  con- 
ditions. To  animals  in  general,  it  is  neither  everywhere 
present  nor  present  under  uniformly  available  conditions — 
it  exists  in  particular  bodies  irregularly  dispersed,  which 
can  be  obtained  only  by  particular  actions.  And  thus, 
change  from  a  general  diffusion  of  food  to  a  localiza- 
tion of  food,  involves  a  further  specialization  of  the  corre- 
spondence. The  organism  now  lives  only  on  condition  that 
contact  with  special  masses  of  matter  shall  be  followed  by 
the  special  acts  required  to  utilize  them.  In  the  Amoeba, 
which  wraps  itself  round  and  gradually  includes  the  small 
nutritive  fragments  it  meets  with,  we  see  that  even  before 
there  are  either  prehensile  or  digestive  organs  the  existence 
of  its  food  in  a  solid  form,  implies  that  the  organism  must 
respond  differently  to  the  contacts  of  solid  matter  and  of 
liquid  matter;  and  this  is  a  progress  towards  speciality  of 
correspondence. 

When  there  arises  the  primary  division  of  the  tissue  into 
stomach  and  skin — when  the  established  differentiation  in 
the  environment  is  met  by  an  established  differentiation  in 
the  organism — when  to  the  ability  to  distinguish  solid  from 
liquid  matter,  comes  to  be  added  the  ability  to  distinguish 


CORRESPONDENCE  AS  INCREASING  IN  SPECIALITY.  331 

different  orders  of  solid  matter  from  one  another;  there 
are  foreshadowed  those  many  higher  specializations  which 
accompany  the  development  of  the  senses.  These  we  have 
now  to  consider. 

§  152.  Out  of  the  primordial  irritability  which  (exclud- 
ing the  indeterminate  types  that  underlie  both  divisions  of 
the  organic  world)  characterizes  animal  organisms  in  gen- 
eral, are  gradually  evolved  those  various  kinds  of  irritability 
which  answer  to  the  various  attributes  of  matter.  The 
fundamental  attribute  of  matter  is  resistance.  The  funda- 
mental sense  is  a  faculty  of  responding  to  resistance.  And 
while  in  the  environment,  associated  with  this  attribute  of 
resistance,  are  other  attributes  severally  distinctive  of  certain 
classes  of  bodies;  in  the  organism,  there  arise  faculties  of 
responding  to  these  other  attributes — faculties  which  enable 
the  organism  to  adjust  its  internal  relations  to  a  greater 
variety  of  external  relations — faculties,  therefore,  which 
increase  the  speciality  of  the  correspondence. 

We  see  this  not  only  in  the  rise  of  the  senses  that  are 
affected  by  the  sapid,  odorous,  visible,  and  sound-producing 
properties  of  things,  but  also  in  the  series  of  phases  through 
which  each  sense  advances  towards  perfection.  For  every 
higher  phase  shows  itself  as  an  ability  to  recognize  smaller 
and  smaller  differences,  either  of  kind  or  degree,  in  the 
attributes  of  surrounding  bodies;  and  so  makes  possible 
still  more  special  adjustments  of  inner  to  outer  relations. 

In  the  case  of  touch,  a  progress  is  early  shown  in  the 
power  to  distinguish  a  large  moving  mass  from  a  small  one 
by  the  force  of  its  collision.  Even  zoophytes,  which  con- 
tract bodily  if  their  tentacles  are  roughly  handled  but  draw 
in  particular  tentacles  only  if  these  are  touched  lightly, 
have  reached  this  stage.  When,  as  in  higher  creatures,  a 
muscular  system  and  a  concomitant  muscular  sense  are 
developed,  there  results  an  appreciation  of  relative  hardness 
in  the  objects  met  with;    as  is  proved  by  the  differences 


332  GENERAL  SYNTHESIS. 

between  the  actions  which  follow  the  contact  with  soft  and 
hard  bodies  respectively.  Afterwards  textures  become  cog- 
nizable, and  also  amounts  of  tenacity;  as  illustrated  in  the 
act  of  a  spider  testing  the  strength  of  its  web.  The  pos- 
session of  well-differentiated  prehensile  organs,  makes  per- 
ceptible the  sizes  and  shapes  of  the  things  laid  hold  of;  and 
the  conduct  is  modified  accordingly.  When  the  combined 
appliances  of  touch  and  muscular  sense  are  fully  developed, 
as  in  man,  we  find  that  between  the  extremes  of  hardness  and 
softness  a  great  number  of  gradations  can  be  appreciated; 
that  an  immense  variety  of  textures  can  be  known  tactually; 
and  that  endless  objects  can  be  identified  by  their  differ- 
ences of  size  and  shape,  ascertained  by  the  fingers  only. 

That  specialized  touch  called  taste,  which  may  be  gene- 
rally, though  not  accurately,  described  as  a  sense  serving  to 
distinguish  soluble  matters  from  insoluble  matters,  presents 
a  series  of  gradations  of  like  kind.  To  the  lower  families 
of  creatures,  which  if  not  without  exception  aquatic  are  in 
all  cases  surrounded  by  a  liquid  that  has  water  for  its  chief 
constituent,  the  insoluble  bodies  are  one  with  the  inorganic 
bodies,  while  the  soluble  mostly  answer  to  the  organic. 
Matter  which  permanently  continues  undissolved  in  the 
sea  or  in  a  river,  is  stone  or  earth;  while  matter  which, 
though  soluble,  is  fouiid  in  a  solid  form,  is  something  that 
is  or  has  been  alive.  Hence,  to  those  lowest  creatures 
which  feed  on  any  organic  substance,  the  soluble  and  the 
insoluble — the  things  that  have  taste  and  the  things  that 
are  tasteless — stand  respectively  for  food  and  not-food. 
From  this  stage  upwards,  successive  specializations,  of 
which  we  may  presume  the  first  to  be  in  an  ability  to  dis- 
tinguish organic  matter  into  animal  and  vegetal,  display 
themselves  in  the  narrowing  of  the  classes  of  things  which 
are  eaten.  Fish  that  take  particular  baits,  insects  and 
quadrupeds  that  feed  on  particular  plants,  illustrate  this. 
Obviously,  it  is  neither  needful  nor  practicable  to  trace  out 
this  progress  in  detail.    It  suffices  to  notice  that  the  higher 


CORRESPONDENCE  AS  INCREASING  IN  SPECIALITY.  333 

animals  perceive  an  increased  number  of  gustable  differ- 
ences; and  that  in  man  the  sense  of  taste,  besides  serving  to 
identify  a  great  variety  of  edible  substances,  aids  the  chemist 
and  the  mineralogist  in  classifying  those  inorganic  com- 
pounds which  are  in  any  degree  soluble. 

Smell  which,  as  before  suggested  (§  140),  has  probably  a 
common  origin  with  touch  and  taste,  and  is  gradually  differ- 
entiated from  them,  passes  through  parallel  stages  of  deve- 
lopment. At  first  a  kind  of  anticipatory  taste,  and  in 
common  with  taste  employed  to  distinguish  nutritive  from 
innutritive  matters,  it  progresses  in  speciality  as  the  food  is 
specialized;  or,  to  put  the  facts  in  logical  order — the  ability 
to  select  special  food  is  usually  dependent  on  the  minuteness 
of  the  differences  which  the  smelling  faculty  can  appreciate. 
This  is  not  so  throughout,  for  prey  is  in  many  cases  recog- 
nized by  other  means  than  scent;  but  it  is  so  with  most 
insects  and  plant-eating  quadrupeds,  as  well  as  with  a 
considerable  proportion  of  creatures  that  are  carnivorous. 
These  gradations  in  the  olfactory  sense,  most  clearly  dis- 
played in  the  mammalia,  reach  in  some  of  those  that  hunt 
by  scent  to  a  great  height.  The  dog  which,  with  nose  to 
the  ground,  traces  out  his  master,  shows  us  that  he  can  do 
more  than  distinguish  by  scent  one  class  of  bodies  from  all 
other  classes:  he  can  even  distinguish  a  particular  individual 
belonging  to  that  class. 

The  increasing  speciality  of  the  correspondences  effected 
by  means  of  vision  as  it  develops  is  still  more  conspicuous. 
The  lowest  form  of  vision  appears  to  be  nothing  beyond  a 
sensitiveness  to  the  proximity  of  a  body  which  intercepts 
the  light.  Such  surrounding  changes  as  cause  marked  ob- 
scurations are  alone  responded  to.  When  the  sensitive  tract 
on  which  the  rays  are  concentrated  is  such  that  a  part  of  it 
can  be  stimulated  without  the  stimulation  of  the  whole,  there 
arises  an  ability  to  perceive  adjacent  objects  by  the  light 
they  reflect.  Dark  and  light  bodies  thus  come  to  be  distin- 
guished; and  we  may  presume  that  further  progress  of  like 


334  GENERAL  SYNTHESIS. 

nature  makes  appreciable  smaller  and  smaller  gradations 
in  the  transitions  from  whiteness  to  blackness:  so  adding  to 
the  number  of  things  discriminated.  An  ability 

to  recognize  differences  in  the  quality  of  the  light  probably 
arises  simultaneously.  Things  that  are  red,  yellow,  and 
blue,  work  unlike  effects  on  the  organism;  as  well  as  those 
that  are  white  and  black.  Familiar  facts  clearly  show  that 
in  the  evolution  of  the  visual  faculty,  the  progress  is  towards 
a  capacity  to  discriminate  a  greater  variety  of  intensities  of 
colour,  of  intermediate  tints,  and  of  degrees  of  light  and 
shade.  As  there  is  developed  a  wider  retina, 

marked  differences  in  the  areas  occupied  by  images  cast  on 
it  become  appreciable ;  and  hence  arises  a  possibility  of  dis- 
tinguishing differences  of  bulk  in  adjacent  objects.  The 
approach  of  a  large  body  changes  the  state  of  a  greater 
portion  of  the  retina  than  the  approach  of  a  small  one:  the 
result  being  an  appropriate  difference  of  action.  And  as  in 
the  case  of  amounts  of  light  and  qualities  of  colour,  succes- 
sive advances  of  this  kind  bring  with  them  perceptions  of 
smaller  unlikeness.  Finally,  there  is  reached 

the  power  to  recognize  not  size  only  but  shape.  A  minuter 
division  of  the  sensitive  tract  into  separate  nervous  elements, 
renders  it  a  fit  instrument  for  this.  Employed  by  an  organ- 
ism of  proportionate  complexity,  an  eye  of  complex  structure 
gives  different  impressions,  both  according  to  the  numbers 
of  its  component  nerve  fibres  simultaneously  affected,  and 
according  to  \hQ^  jpa/rticula/r  coTribinations  oi  them  simultane- 
ously affected;  and  the  particular  combinations,  varying  as 
they  do  with  the  forms  of  the  bodies  seen,  serve  as  stimuli  to 
the  properly-adjusted  actions.  All  which  several  kinds  of 
visual  development,  reaching  great  heights  among  the 
superior  animals,  unite  in  giving  man  the  power  to  identify 
by  the  eye  innumerable  different  objects;  and  so  to  make 
innumerable  special  adaptations  in  his  conduct. 

Similarly  with  hearing.    At  first  nothing  but  a  sensitive- 
ness to  concussions  affecting  the  whole  environment,  this 


CORRESPONDENCE  AS  INCRBASINa  IN  SPECIALITY.  335 

sense,  when  localized  and  developed,  becomes  a  means  of 
distinguishing  the  strengths  of  the  vibrations.  A  mode- 
rate sound  near  the  auditory  organ  produces  a  different 
effect  from  one  causing  a  violent  tremor  of  the  whole 
surrounding  fluid ;  and  slowly  as  the  multiplying  apparatus 
of  which  the  ear  essentially  consists,  is  developed,  more 
numerous  degrees  of  intensity  become  perceptible.  The  re- 
sult we  see  in  animals  which  listen,  or  pursue,  or  seek  refuge, 
according  as  some  neighbouring  noise  is  faint,  or  mode- 
rate, or  startling.  Higher  endowments  of  the 
faculty  are  also  accompanied  by  increased  ability  to  dis- 
criminate qualities  as  well  as  quantities  of  sounds.  Birds 
which  answer  one  another  in  the  woods  and  which  when 
caged  may  be  taught  definite  melodies,  must  recognize 
many  differences  in  pitch.  Parrots,  whose  imitations 
exhibit  great  variety  in  timhre  as  well  as  great  com- 
pass, show  a  power  to  appreciate  those  secondary  quali- 
ties by  which  tones  of  the  same  pitch  are  distinguished 
from  one  another.  By  most  domestic  quadrupeds,  especi- 
ally such  as  answer  to  their  names,  marked  contrasts  of 
pitch,  or  of  timbre^  or  of  both,  are  responded  to.  And 
among  men  the  auditory  faculty  reaches  a  development 
which,  besides  enabling  them  to  recognize  numerous  adja- 
cent creatures,  various  mechanical  operations,  countless 
natural  phenomena,  by  the  accompanying  sounds,  also 
enables  them  to  identify  unseen  persons  by  the  loudness, 
pitch,  and  tvmbre  of  their  voices,  and  even  to  perceive,  the 
particular  states  of  feeling  in  which  such  persons  then  are. 

Throughout  the  animal  kingdom,  then,  the  specialization 
of  the  senses  measures  the  specialization  of  the  cor- 
respondences between  inner  and  outer  relations — is  a  means 
to  this  specialization.  Alike  in  the  differentiation  of  the 
senses  from  one  another,  in  the  differentiation  of  each 
sense  into  the  divisions  which  eventually  constitute  it,  and 
in  the  differentiations  of  these  into  the  minute  subdivi- 
sions that  make  possible  the  appreciation  of  minute  dis- 


336  GENERAL  SYNTHESIS. 

tinctions,  we  see  a  succession  of  subjective  modifications 
fitting  the  organism  to  respond  to  a  greater  and  greater 
number  of  those  objective  modifications  which  characterize 
things  in  its  environment. 

§  153.  While  the  developing  faculties  of  touch,  taste, 
smell,  sight,  and  hearing,  have  been  making  it  possible  for 
the  organism  to  respond  to  smaller  differences  in  the  simpler 
properties  of  things,  there  has  been  growing  up  a  power  of 
responding  to  those  more  complex  properties  of  things  which 
are  not  cognizable  by  sensation  alone.  This  makes  its 
appearance  so  gradually,  and  is  so  intimately  associated 
with  the  direct  functions  of  the  senses,  that  it  is  scarcely 
possible  to  treat  of  the  one  without  in  some  degree  involv- 
ing the  other.  Indeed,  the  boundary  line  was  crossed  in 
the  foregoing  section,  when  speaking  of  visible  and  of 
tangible  form,  and,  to  a  smaller  extent,  in  other  cases. 

The  essential  nature  of  this  higher  order  of  specialized 
correspondences  will  be  more  conveniently  considered  here- 
after under  another  head.  For  the  present  it  will  suffice 
to  say,  that  they  are  seen  wherever  Space  or  Time,  or  both 
Space  and  Time,  are  involved.  Let  us  look  at  the  matter 
in  the  concrete. 

Observe,  first,  that  in  itself  extension  of  the  correspon- 
dence in  Space  implies  increased  speciality  of  correspon- 
dence, differing  in  kind  from  that  above  described  though 
inseparable  from  it  in  origin.  A  higher  development  of  the 
eye,  brings  simultaneously  a  greater  ability  to  identify  dis- 
tant objects  and  a  greater  ability  to  discriminate  between  the 
sizes  of  near  objects.  And  it  is  clear  that  these  connate 
abilities  to  identify  objects  at  a  distance  and  to  appreciate 
differences  of  apparent  magnitude,  give  together  a  power  of 
estimating  distance:  whence  arise  differences  of  action, 
according  as  the  perceived  enemies  or  prey  are  dangerously 
near  or  hopelessly  remote ;  and  these  differences  of  action  im- 
ply a  new  series  of  special  correspondences.  Mani- 


CORRESPONDENCE  AS  INCREASING  IN  SPECIALITY.  337 

festly,  also,  extension  of  the  correspondence  in  Time  in- 
volves analogous  results.  When,  instead  of  recognizing 
only  brief  mechanical  sequences  which  occur  close  to  it,  the 
organism  recognizes  mechanical  sequences  of  longer  dura- 
tion, and  afterwards  non-mechanical  sequences;  and  when, 
as  a  consequence,  instead  of  meeting  all  sequences  involving 
dangers  by  some  one  kind  of  defensive  action,  as  retreat  into 
its  shell,  it  becomes  able  to  meet  them  by  different  actions 
according  to  their  lengths;  the  correspondence  is,  by  im- 
plication, rendered  more  special. 

This  being  understood,  it  will  be  seen  that  when  the 
speciality  of  correspondence  which  exhibits  itself  in  dis- 
criminating objects  from  one  another,  is  united  with  the 
speciality  of  correspondence  which  exhibits  itself  in  dis- 
criminating distmices  in  Space  or  Time,  there  arises  a  new 
and  a  higher  order  of  special  correspondences;  or  more 
correctly — the  previously-specialized  correspondences  are 
further  specialized.  And  when,  as  during  this  same  pro- 
gress, there  is  developed  a  power  of  recognizing  direction 
in  space,  the  speciality  is  again  increased.  To  another  set 
of  distinctions  in  the  environment,  there  is  another  set  of 
adjustments  in  the  organism.  These  general  truths  will  be 
best  elucidated  by  a  few  illustrations. 

On  the  approach  of  any  large  body,  the  shrimps  left  in  a 
tide-pool  make  convulsive  darts  which  may  end  in  removing 
each  of  them  to  a  greater  distance  from  the  approaching 
body,  or  in  bringing  it  nearer,  or  in  leaving  it  almost  where 
it  was.  The  random  leaps  which  a  flea  makes  in  attempting 
to  escape  are  of  like  nature ;  showing,  as  they  do,  no  percep- 
tion of  the  whereabouts  of  the  pursuer.  On  the  other 
hand,  the  movements  of  a  crab  or  a  fish  when  alarmed,  are, 
like  those  of  all  higher  creatures,  a/way  from  the  object  to 
be  escaped.  The  particular  direction  of  something  in  the 
environment  is  responded  to  by  appropriately-adjusted 
motions  of  the  organism — the  correspondence  is  compara- 
tively special.    When,  again,  not  only  the  direction  but  the 


338  GENERAL  SYNTHESIS. 

nature  of  a  neighbouring  body  is  known,  either  by  its  colour, 
or  by  the  sound  it  makes,  or  by  both — as  exemplified  in  the 
deer  that  gallops  away  from  a  creature  that  barks  but  not 
from  one  that  bleats,  in  the  bee  that  flies  towards  a  flower, 
in  the  trout  that  rises  at  one  object  but  not  at  another — 
there  is  a  still  further  specialization.  And  when  magnitudes 
and  forms  and  distances  also  come  to  be  appreciated,  there 
result  those  more  definitely-adjusted  actions  by  which  the 
higher  animals  elude  danger  and  secure  prey — actions  such 
as  those  of  the  chamois  springing  from  crag  to  crag,  of  the 
hawk  pouncing  on  its  quarry,  of  the  dog  catching  the 
morsel  of  food  thrown  to  it,  of  the  bird  building  its  nest 
and  feeding  its  young. 

Similarly,  that  increased  speciality  implied  by  extension 
of  the  correspondence  in  Time,  when  joined  with  that  in- 
creased speciality  implied  by  a  better  discrimination  of 
objects,  gives  origin  to  a  further  series  of  higher  specia- 
lizations. As  fast  as  the  sequences  which  are  perceived  to 
differ  in  length  become  more  numerous;  and  as  fast  as 
there  is  a  multiplication  of  things  distinguished  from  one 
another;  so  fast  do  the  adjustments  of  the  organism  to 
special  actions  going  on  around  it  augment  in  number  geo- 
metrically. Save  in  respect  to  rapid  mechanical  changes,  no 
correspondences  of  this  order  are  shown  by  the  lower  classes 
of  creatures ;  and,  lacking  as  they  do  the  ability  to  estimate 
time,  even  the  higher  mammals  supply  but  few  and  im- 
perfect examples  of  it.  The  lion  that  goes  to  the  river-side 
at  dusk  to  lie  in  wait  for  creatures  coming  to  drink,  and 
the  house-dog  standing  outside  the  door  in  expectation 
that  some  one  will  presently  open  it,  may  be  cited  as  approxi- 
mative instances.  But  only  when  we  come  to  the  human 
race  are  correspondences  of  this  degree  of  speciality  ex- 
hibited with  distinctness  and  frequency.  In  preparing  his 
weapons  against  the  approaching  immigration  of  certain 
birds,  in  putting  aside  to  dry  the  skins  which  he  preserves 
for  clothing,  in  making  the  fire  by  which  to  cook  his  food, 


CORRESPONDENCE  AS  INCREASING  IN  SPECIALITY.  339 

the  savage  adapts  his  conduct  to  the  special  changes  under- 
gone by  special  bodies  during  definite  intervals. 

Eventually  there  is  reached  speciality  alike  in  space, 
time,  and  object — the  action  of  the  organism  is  adjusted  to 
the  changes  of  a  particular  thing  in  a  particular  spot  at  a 
particular  period.  A  large  proportion  of  human  actions, 
even  among  the  uncivilized,  are  of  this  nature.  The  going 
to  certain  places,  at  certain  seasons,  to  gather  certain 
natural  productions  then  fit  for  use;  the  endeavour  to 
intercept  an  animal  that  is  making  for  a  retreat,  by  getting 
there  before  it;  these,  and  numerous  daily  procedures,  will 
serve  as  examples. 

§154.  Under  this,  as  under  previous  aspects,  an  advance 
of  the  correspondence  is  clearly  displayed  in  the  course  of 
human  progress.  The  growth  of  classifications  implies  the 
establishment  of  more  numerous  distinctions  among  sur- 
rounding things,  and  a  conforming  of  the  conduct  to  their 
respective  properties.  Agriculture,  as  it  develops,  brings 
knowledge  of  the  serial  changes  undergone  by  various 
plants  and  animals;  while  special  materials,  times,  modes, 
places,  are  adopted  for  the  production  of  each.  Improve- 
ments in  the  Arts  have  involved  an  incalculable  multiplica- 
tion of  special  processes  adapted  to  produce  special  changes 
in  special  objects.  Our  whole  social  life,  alike  in  the  manu- 
factory, in  the  shop,  on  the  highway,  in  the  kitchen,  displays 
throughout,  the  performance  of  particular  actions  towards 
particular  things  in  particular  places  at  particular  times. 

Above  all  in  exact  science,  or  rather  in  the  actions 
guided  by  exact  science,  civilization  presents  us  with  a  new 
and  vast  series  of  correspondences  far  exceeding  in  speciality 
those  that  came  before  them.  For  this  which  we  call  exact 
science  is  in  reality  qitantitatwe  jyrevision,  as  distinguished 
from  that  qualitative  jpremsion  constituting  ordinary  know- 
ledge. The  progress  of  intelligence  has  given  the  ability  to 
say  both  that  such  and  such  things  are  related  in  co- 


840  GENERAL  SYNTHESIS. 

existence  or  sequence,  and  that  the  relation  between  them 
involves  such  and  such  amounts  of  space,  time,  force,  tem- 
perature, &c.,  &c.  It  has  become  possible  to  predict,  not 
simply  that  under  given  conditions  two  things  will  always 
be  found  together,  but  to  predict  how  much  of  the  one  will 
be  found  with  so  much  of  the  other.  It  has  become  possible 
to  predict,  not  simply  that  this  phenomenon  will  occur  after 
that,  but  to  predict  the  exact  time  at  which  it  will  occur, 
or  the  exact  distance  in  space  at  which  it  will  occur,  or 
both.  And  manifestly,  this  reduction  of  objective  pheno- 
mena to  definite  measures  gives  to  those  subjective  actions 
that  correspond  with  them,  a  degree  of  precision,  a  special 
fitness,  greatly  beyond  that  possessed  by  ordinary  actions. 
There  is  an  immense  contrast  in  this  respect  between  the 
doings  of  the  astronomer  who,  on  a  certain  day,  hour,  and 
minute,  adjusts  his  instrument  to  watch  an  eclipse,  and 
those  of  the  farmer  who  so  arranges  his  work  that  he  may 
have  hands  enough  for  reaping  some  time  in  August  or 
September.  The  chemist  who  calculates  how  many  pounds 
of  quick-lime  will  be  required  to  decompose  and  precipitate 
all  the  bi-carbonate  of  lime  which  the  water  in  a  given 
reservoir  contains  in  a  certain  per-centage,  exhibits  an 
adjustment  of  inner  to  outer  relations  incomparably  more 
specific  than  does  the  laundress  who  softens  a  tub-full  of 
hard  water  by  a  handful  of  soda.  In  their  adaptations  to 
external  co-existences  and  sequences,  there  is  a  wide  differ- 
ence between  the  proceedings  of  ancient  besiegers  whose 
battering  rams  were  indeterminate  in  their  actions,  and  those 
of  modem  artillery-officers,  who,  by  means  of  a  specific 
quantity  of  powder,  consisting  of  specific  ingredients,  in 
specific  proportions,  placed  in  a  tube  at  a  specific  inclina- 
tion, send  a  bomb  of  specific  weight,  on  to  a  specific  object, 
and  cause  it  to  explode  at  a  specific  moment.  And  when 
we  bear  in  mind  that  science,  considered  as  the  development 
of  qualitative  prevision  into  quantitative  prevision,  is  not 
only  thus  distinguished  by  the  relatively-high  speciality  of 


CORRESPONDENCE  AS  INCREASING  IN  SPECIALITY.  341 

the  correspondences  it  achieves,  but  that,  as  contemplated 
in  its  own  progress,  it  has  been  ever  becoming  more  accu- 
rately quantitative,  more  special  in  its  previsions;  it 
becomes  obvious  that  even  the  most  transcendent  achieve- 
ments of  rationality  are  but  the  carrying  further  that 
specialization  of  the  correspondences  between  the  organism 
and  its  environment,  which  commences  with  the  evolution 
of  Life  in  general. 

§  155.  This  increase  in  the  speciality  of  the  correspond- 
ence, like  its  extension  in  Space  and  Time,  is  both  in  itself 
a  higher  life,  and  contributes  to  greater  length  of  life. 
Inability  to  distinguish  between  surrounding  bodies  of 
different  natures,  must  be  attended  by  fatal  errors  in  the 
conduct  pursued  towards  them;  while,  conversely,  the 
greater  the  power  to  recognize  the  multitudinous  distinc- 
tions among  such  bodies,  the  greater  must  be  the  number 
of  special  adjustments  that  can  be  made  to  them,  and  the 
more  frequent  will  be  the  self-preservation.  The  proposi- 
tion is  in  essence  a  truism.  It  is  almost  a  truism,  too,  to 
say  that  in  proportion  to  the  numerousness  of  the  objects 
that  can  be  distinguished,  and  in  proportion  to  the  variety 
of  co-existences  and  sequences  that  can  be  severally  re- 
sponded to,  must  be  the  number  and  rapidity  and  hetero- 
geneity of  the  changes  going  on  within  the  organism — 
must  be  the  amount  of  vitality.  Indeed,  there  is  no  single 
formula  which  so  well  expresses  the  progress  of  Life,  as 
this  increase  in  the  speciality  of  the  correspondences  between 
inner  and  outer  relations.  For,  taking  the  extreme  case,  it 
is  clear  that  did  the  actions  of  an  organism  accurately 
respond  to  all  the  co-existences  and  sequences  of  all  things 
whatever  in  its  environment,  its  life  would  be  eternal.  And 
it  is  equally  clear  that  the  innumerable  internal  changes 
involved  in  effecting  the  correspondence  with  innumerable 
external  relations,  would  imply  the  highest  conceivable 
degree  of  vital  activity. 


CHAPTER  yn. 

THE    COEEESPONDENCE    AS    INCEEASING    IN    GENEBALITY. 

§  156.  The  adjustment  of  inner  to  outer  relations  pro- 
gresses in  generality  at  the  same  time  that  it  progresses  in 
speciality.  This  statement  seems  to  involve  a  contradiction, 
but  the  contradiction  is  verbal  only — the  generality  here 
referred  to  being  of  a  different  order  from  that  which  pre- 
cedes speciality. 

Primitive  correspondences  are  general  in  the  sense  that 
those  relations  in  the  environment  to  which  organic  rela- 
tions respond,  are  everywhere  present  and  continuously 
present.  During  a  summer's  day,  light,  heat,  and  carbonic 
acid,  bathe  all  the  leaves  of  a  plant;  and  the  dependent 
chemical  changes  within  the  plant,  go  on  for  as  many  hours 
as  the  surrounding  elements  and  actions  remain  in  the  same 
relation.  Hence  the  correspondence,  involving  neither  any 
special  point  in  space  nor  any  special  movement  in  time,  is  of 
a  very  general  nature.  And  the  like  holds  with  those  in- 
ferior animals  to  which  the  environment  presents  both  the 
disintegrating  matter  and  the  integrable  matter  in  diffused 
forms.  The  generalities,  however,  to  which  the  organism 
responds  more  and  more  the  higher  it  advancei,  are  not 
those  exhibited  by  the  mass  of  the  environing  medium,  but 
those  exhibited  by  the  individual  objects  it  contains;  and 
gieneralities  of  this  kind  become  cognizable  only  as  in- 
telligence is  developed.     Relations  in  the  organism  corre- 

842 


COflllESPONDENCB  AS  INCREASING  IN  GENERALITY.  343 

spending  to  relations  displayed  in  common  by  several  diffe- 
rent groups  of  bodies,  but  not  by  other  groups,  can  be 
established  only  when  the  organism  has  such  experiences  of 
various  groups  of  bodies  as  enable  it  to  distinguish  among 
them.  Only  when  there  come  to  be  recognized  many 
different  classes  of  objects,  can  there  possibly  arise  sub- 
jective generalities  parallel  to  those  objective  generalities 
which  bind  together  classes  of  objects  superficially  unlike. 

There  are  indeed  generalities  which  diminish  in  extensive- 
ness  as  the  specialities  increase  in  number — generalities 
which  form  the  material  out  of  which  specialities  are  pro- 
duced by  continual  subdivision.  The  growth  of  a  response 
to  the  distinction  between  liquid  matter  and  solid  matter, 
then  to  the  distinctions  between  liquid,  inorganic,  and  organic 
matters,  afterwards  to  those  between  liquid,  inorganic,  vege- 
tal, and  animal  matters,  implies  a  correspondence  to  gene- 
ralities that  are  step  by  step  less  comprehensive;  and  each 
further  multiplication  of  classes  supposes  a  further  reduction 
in  the  number  of  examples  which  each  sub-class  includes. 
These,  however,  are  generalities  which,  under  their  obverse 
aspect,  we  considered  in  the  last  chapter.  For  all  special 
correspondences  are  really  the  manifestations  of  general 
correspondences  covering  certain  groups  of  cases.  The  pre- 
cautionary acts  of  a  barn-door  fowl  on  seeing  a  hawk  hover- 
ing above,  are  related  to  the  acts  of  that  hawk  in  particular, 
only  as  being  like  the  acts  of  hawks  in  general.  The  corre- 
spondence is  special,  only  in  the  sense  of  referring  to  the 
small  class,  hawks,  instead  of  to  the  large  class,  birds. 

But  that  advancing  generality  of  correspondence  here  to 
be  contemplated,  shows  itself  in  the  recognition  of  con- 
stant co-existences  and  sequences  other  than  those  which 
characterize  special  classes — co-existences  and  sequences 
common  to  many  classes  that  have  come  to  be  regarded 
as  entirely  unlike.  Instead  of  being  seen  in  a  response 
to  the  constant  relation  between  a  particular  scent,  and 
the  colour,  size,  form,  actions,  and  cries,  of  the  creature 


344  GENERAL  SYNTHESIS. 

possessing  it;  this  progress  is  seen  in  adjustments  to  such 
relations  as  those  between  bulk  and  weight,  inanimateness 
and  passivity — relations  which  extend  beyond  class  limits, 
and  obtain  under  great  dissimilarities.  Obviously  the 
growth  of  generalities  of  this  order  must  be  opposite  in 
direction  to  the  growth  of  the  preceding  ones. 

To  trace  up  this  growth  from  the  lower  to  the  higher 
forms  of  life,  after  the  manner  pursued  in  previous  chapters, 
is  extremely  difficult  if  not  impossible.  For  this  species 
of  correspondence  does  not  manifest  itself  in  distinct,  un- 
combined  forms.  The  extensions  of  the  correspondence  in 
Space  and  Time,  as  well  as  its  increase  in  Speciality,  are 
experimentally  demonstrable;  but  an  internal  relation 
parallel  to  some  external  relation  which  is  not  peculiar  to 
special  classes  of  things,  cannot  be  separately  identified  in 
the  conduct.  Giving  origin  to  no  particular  acts,  but  serving 
simply  to  modify  the  acts  otherwise  originated,  it  can  be 
discovered  only  by  analysis  of  these. 

Hence  our  course  must  be  to  ascertain  the  conditions 
under  which  alone  advance  of  the  correspondence  in  gene- 
raUty  becomes  possible;  and  then  to  show  how  the  pro- 
cesses of  evolution  already  described,  give  rise  to  these 
conditions.    Let  us  do  this. 

§  157.  The  establishment  of  a  generality  of  this  higher 
kind,  embracing  classes  superficially  dissimilar,  implies  a 
power  of  recognizing  aWrihutea  as  distinguished  from  the 
objects  possessing  them.  Before  any  two  properties  that  are 
found  together  under  many  varieties  of  size,  form,  colour, 
texture,  temperature,  motion,  &c.,  can  have  their  constant 
relation  of  co-existence  responded  to  by  the  organism,  the 
organism  must  be  able  to  identify  these  two  properties, 
as  separate  from  their  accidental  accompaniments.  The 
formation  of  special  class-generalities,  which  group  together 
clusters  of  phenomena  that  greatly  resemble  one  another  in 
all  respects,  requires  no  distinct  parting  of  attributes.    But 


CORRESPONDENCE  AS  INCREASING  IN  GENERALITY.  345 

where  the  resemblance  is  confined  to  some  one  essential 
relation  common  to  many  cases  which  in  other  respects 
differ,  it  is  clear  that  unless  the  elements  of  this  relation 
are  separately  cognizable  there  can  be  no  response  to  it. 

And  now  the  truth  to  be  noted  is  that  increase  of  the 
correspondence  in  speciality,  inevitably  brings  about  this 
parting  of  attributes.  There  cannot  be  a  multiplication 
of  distinguishable  classes,  without  there  being  a  simul- 
taneous approach  to  the  perception  of  properties  as  distinct 
from  objects.  For  if,  ascending  from  the  lowest  creatures 
by  which  but  few  attributes  are  cognizable,  we  advance  to 
those  capable  of  being  impressed  by  a  greater  and  greater 
number  of  attributes,  it  is  clear  that  in  proportion  as  the 
groups  of  attributes  become  increasingly  varied  and  special, 
there  must  be  more  frequent  dissociations  of  particular  atr 
tributes  from  the  rest.  Forms,  colours,  sizes,  sounds, 
scents,  motions,  are  found  in  all  combinations.  These  two 
kinds  of  animals  are  alike  in  everything  but  colour;  those 
two  agree  in  colour  but  differ  in  form  and  scent;  and  the 
others  have  little  in  common  but  size.  The  property  A 
occurs  here  along  with  the  properties  B,  C,  D ;  there  along 
with  C,  F,  H;  there  along  with  E,  G,  B;  and  so  on  with 
each  property  to  a  greater  or  less  extent.  Hence  it  must 
happen  that  by  multiplication  of  experiences,  the  impres- 
sions produced  by  these  properties  on  the  organism  will  be 
disconnected,  and  rendered  so  far  independent  in  the  organ- 
ism as  the  properties  are  in  the  environment.  Whence 
must  eventually  result  a  power  to  recognize  attributes  in 
themselves,  apart  from  particular  bodies. 

It  may,  indeed,  be  shown  that  progress  of  the  corre- 
spondence in  speciality,  itself  becomes  possible  only  in  pro- 
portion to  the  progress  of  this  analysis.  An  analogy  will 
best  show  the  dependence.  Let  a  chemist  be  required  to 
produce  artificially  sundry  compound  bodies;  what  is 
implied  in  the  execution  of  his  task?  The  implication  is 
that  he  knows  the  composition  of  each  of  these  bodies. 


346  GENERAL  SYNTHESIS. 

But  what  does  knowledge  of  their  composition  pre-suppose? 
It  pre-supposes  that  they  have  been  severally  resolved  into 
their  constituents.  And  the  formation  of  each  required 
compound  implies  that  its  constituents  are  united  in  the 
right  proportions.  Well,  the  process  of  identifying  any 
object  is  a  synthesis  of  impressions,  corresponding  to 
certain  united  properties  which  the  thing  displays;  and 
similarly  implies  a  recognition  of  the  separate  impressions 
which  correspond  with  the  separate  properties.  The 
botanist  who  knows  a  particular  flower  not  by  the  fructifi- 
cation alone,  in  which  it  is  like  many  others — not  by  the 
number  of  its  petals,  which  is  a  usual  number — not  by  their 
forms  in  which  they  do  not  differ  from  these,  nor  by  their 
colours  in  which  they  do  not  differ  from  those — not  by  the 
calyx,  nor  the  bracts,  nor  the  leaves,  nor  the  stalk,  sepa- 
rately considered,  but  by  all  these  taken  together;  obvi- 
ously effects  the  identification  by  a  synthesis  of  attributes. 
And  that  which  he  does  in  a  deliberate  and  conscious 
way,  is  done  consciously  or  unconsciously  in  every  case 
where  an  object  is  recognized  as  of  special  nature — is 
done  in  a  degree  proportionate  to  the  speciality  of  the 
correspondence.  Should  it  be  said  that  this  state- 

ment contradicts  the  previous  statement,  since  the  one 
represents  the  analysis  of  attributes  as  a  pre-requisite  to 
speciality  of  correspondence,  while  the  other  represents  the 
analysis  of  attributes  as  resulting  from  increase  of  the  cor- 
respondence in  speciality,  the  reply  is  that  the  two  processes 
go  on  in  mutual  dependence,  perpetually  acting  and 
reacting  on  each  other.  Every  advance  in  speciality  pre- 
sently renders  the  analysis  of  attributes  more  precise;  and 
each  step  in  the  analysis  of  attributes  makes  possible  a 
higher  speciality. 

Thus  the  course  of  evolution  described  in  previous 
chapters,  is  necessarily  accompanied  by  a  disentangling  of 
properties  from  one  another,  ending  in  an  ability  to  recog- 
nize them  in  the  abstract.    Later  and  more  slowly,  relations 


CORRESPONDENCE  AS  INCREASING  IN  GENERALITY.  347 

both  of  sequence  and  of  co-existence  must  come  to  be 
discriminated  one  from  another,  and  segregated  into  kinds 
and  degrees  of  relations.  An  increasing  speciality  in  the 
adjustments  to  mechanical  changes,  pre-supposes  an  in- 
creasing decomposition  of  such  changes  into  their  elements 
— a  growing  power  to  distinguish  velocity  of  motion, 
direction  of  motion,  acceleration  and  retardation  of  motion, 
kind  of  motion  in  respect  of  simplicity  or  complexity,  and 
so  on;  and  where  non-mechanical  sequences  also  come  to 
be  responded  to,  a  parallel  analysis  must  accompany  a 
parallel  progress  in  speciality. 

When  these  analyses  have  been  considerably  extended, 
there  arises,  and  only  then  arises,  a  possibility  of  advance  in 
generality  of  correspondence.  Relations  between  properties 
possessed  in  common  by  objects  of  widely  different  kinds, 
can  be  perceived  as  soon  as  these  properties  are  separately 
cognizable.  And  a  still  higher  progress  in  the  specializa- 
tion of  the  correspondences,  ultimately  brings  about  this 
remaining  step  required  for  generalization  of  them.  For  if, 
as  we  have  seen,  the  multiplication  of  special  correspon- 
dences must  be  accompanied  by  the  dissociation  of  variably- 
united  attributes;  then,  when  the  variably-united  attri- 
butes displayed  by  a  group  of  different  classes  have  been  as 
it  were  disintegrated  in  the  consciousness  of  the  organism, 
the  attributes  that  have  not  been  disintegrated  must  begin 
to  stand  out  from  the  rest,  as  remaining  always  constant 
amid  these  inconstancies.  Hence  there  must  be  established 
in  the  organism  a  constant  relation  corresponding  to  the 
constant  relation  between  these  attributes;  and  this  consti- 
tutes the  advance  in  generality  we  are  looking  for.  Fur- 
ther, as  the  comparatively-constant  relations  thus  first 
generalized  from  the  experience  of  but  few  classes,  will,  in 
the  majority  of  cases,  be  proved  by  wider  experience  to  be 
not  everywhere  constant;  and  as,  by  the  accumulation  of 
these  wider  experiences,  the  same  process  must  be  gone 
through  with  the  comparatively-constant  relations  as  before 


348  GENERAL  SYNTHESIS. 

with  the  inconstant  ones,  with  the  result  of  bringing  the 
still  more  constant  relations  into  view;  the  progress  must 
be  from  narrow  generalizations  to  wider  and  wider  ones. 
And  this  we  know,  d  jposteriori,  to  be  the  law  which  the 
progress  conforms  to. 

§  158.  These  explanations  will  at  once  show  why  the 
increase  of  the  correspondence  in  generaUty  is  scarcely  dis- 
cernible in  any  but  the  most  intelligent  creatures.  Neces- 
sary as  it  is  that  there  should  be  a  great  advance  in  the 
speciality  of  the  correspondences  to  produce  the  requisite 
separation  of  attributes;  and  necessary  as  yet  further  ad- 
vance in  specialization  is  to  bring  into  view  the  constantly  re- 
lated attributes  as  distinguished  from  the  inconstantly-re- 
lated ones;  it  is  only  when  that  developed  speciality  of  corre- 
spondence characterizing  superior  creatures  is  reached,  that 
progress  in  generality  of  correspondence  can  begin.  Hence 
the  fact  that  while  the  higher  mammals  undoubtedly  display 
some  generalities  of  correspondence  of  the  least  abstract 
kind,  it  is  only  in  the  human  race  that  this  species  of  ad- 
justment of  inner  to  outer  relations  becomes  conspicuous. 

Human  progression,  however,  exhibits  to  us,  under  this 
as  under  previous  aspects,  an  immense  increase  in  the  har- 
mony between  the  organism  and  its  environment.  Perhaps 
in  no  respect  is  the  increasing  correspondence  wrought  out 
by  civilization  more  conspicuous  than  in  the  growth  of 
generalizations,  ever  more  numerous  and  more  compre- 
hensive. The  enormous  expansion  of  science  which  these 
latter  ages  have  witnessed,  mainly  consists  in  the  union  of 
many  particular  truths  into  general  truths,  and  in  the  union 
of  many  general  truths  into  truths  still  more  general.  Illus- 
trations are  needless;  for  the  proposition  is  familiar  and 
admitted  by  all.  It  is  enough  simply  to  point  to  this  great 
phenomenon  as  one  of  the  many  forms  of  the  evolution  we 
are  tracing  out. 

A  mere  mention,  too,  of  the  fact  that  the  generalizations 


CORRESPONDENCE  AS  INCREASING  IN  GENERALITY.  349 

of  science  immensely  advance  the  arts,  and  through  the  arts 
minister  to  human  welfare,  will  serve  to  show  that  increase 
of  the  correspondence  in  generality,  like  its  other  modes  of 
increase,  makes  possible  a  greater  duration  of  life.  And  a 
like  brief  reference  to  the  concentration  of  thoughts  and 
complexity  of  conceptions,  which  these  wider  generaliza- 
tions imply,  will  sufficiently  indicate  the  higher  degree  of 
life  which  accompanies  this  greater  length  of  life. 


CHAPTER  Vm. 

THE    COEEESPONDENCE    AS    INCBEASING    IN    COMPLEXITY. 

§  159.  Another  change  in  our  stand-point  affords  us  a 
view  of  progressing  vitality  which,  though  not  the  same  in 
range  with  foregoing  views,  has  much  in  common  with 
them.  As  we  saw  that  the  extensions  of  the  correspondence 
in  Space  and  in  Time,  are  partly  reciprocal  and  partly 
not  so — as  we  saw  that  increase  of  the  correspondence  in 
Speciality,  while  to  some  degree  comprised  under  the  exten- 
sions in  Space  and  Time,  includes  very  much  beside ;  so  we 
shall  see  that  while,  throughout  a  certain  range  of  cases, 
growing  Complexity  is  the  same  thing  as  growing  Speciality, 
yet  neither  includes  all  that  the  other  does.  Much  of  the 
early  advance  in  Speciality  does  not  imply  advance  in  Com- 
plexity; and  the  higher  forms  of  the  advance  in  Complexity 
cannot  without  straining  be  comprehended  under  advance 
in  Speciality. 

§160,  Wherever  we  find  nothing  but  a  greater  ability  to 
discriminate  between  varieties  of  the  same  simple  pheno- 
menon, there  is  increased  speciality  of  correspondence  with- 
out increased  complexity.  It  is  thus  with  the  progress 
from  an  eye  that  appreciates  a  difference  between  light  and 
darkness,  to  one  that  appreciates  degrees  of  difference  be- 
tween them,  and  afterwards  to  one  that  appreciates  differ- 
ences of  colour  and  degrees  of  colour.    It  is  thus  with  the 

850 


CORRESPONDENCE  AS  INCREASING  IN  COMPLEXITY.  351 

progress  from  the  power  of  distinguishing  a  few  strongly- 
contrasted  smells  or  tastes,  to  the  power  of  distinguishing 
many  slightly-contrasted  smells  or  tastes.  It  is  thus  with 
the  progress  from  that  lowest  form  of  hearing  shown  by  a 
response  to  any  violent  tremor  of  the  surrounding  fluid,  to 
those  higher  forms  of  it  in  which  differences  of  loudness  are 
recognized,  and,  by  and  by,  differences  of  pitch  and  timbre. 
The  insect  which  lays  its  eggs  only  on  a  plant  having  a 
particular  odour,  or  the  bird  which  is  alarmed  by  a  tone  of 
a  certain  pitch  but  not  by  a  tone  of  another,  shows  an 
adjustment  of  inner  to  outer  relations  equally  simple  with 
that  shown  by  the  snail  which  withdraws  into  its  shell  on 
being  touched.  Though  the  stimulus  responded  to  is  more 
special,  it  is  not  more  complex.  In  each  case  a  single 
undecomposable  sensation  is  followed  by  certain  muscular 
actions;  and  though  these  muscular  actions  are  more  intri- 
cate in  the  higher  creatures  than  in  the  lower,  yet  the 
relation  between  antecedents  and  consequents  is  very 
nearly,  if  not  quite,  of  the  same  order.  But  where  the 
stimulus  responded  to  consists,  not  of  a  single  sensation 
but  of  several,  or  where  the  response  is  not  one  action  but 
a  group  of  actions,  the  increase  in  speciality  of  correspon- 
dence results  from  an  increase  in  its  complexity. 

The  development  of  vision  repeatedly  illustrates  this. 
When,  after  that  response  to  the  habitual  relation  between 
opacity  and  solidity,  which  is  first  established,  there  arises 
a  response  to  the  relation  between  solidity  and  power  to 
reflect  light — when  differences  in  the  amounts  and  qualities 
of  reflected  light  come  to  be  recognized  in  connexion  with 
differences  of  bulk — when  there  is  acquired  an  ability  to 
identify  objects  by  form,  as  well  as  by  colour  and  size  con- 
joined ;  it  is  manifest  that  each  successive  stage  implies  the 
appreciation  of  larger  clusters  of  attributes.  The  impres- 
sion received  by  the  organism  from  each  object  is  a  more 
complex  impression — is  increasingly  heterogeneous.  And 
when  not  only  colour,  size,  and  shape  become  cognizable, 


852  GENERAL  SYNTHESIS. 

but  also  direction  in  space,  distance  in  space,  motion,  kind 
of  motion,  direction  of  motion,  velocity  of  motion — when, 
as  by  a  falcon  swooping  on  its  quarry,  all  these  external 
relations  are  simultaneously  responded  to;  it  is  clear  that 
the  guiding  perception  must  be  compounded  of  many  ele- 
ments. There  is  no  need  to  dwell  on  this  truth 
as  further  exemplified  during  the  evolution  of  the  other 
senses;  nor  to  trace  up  in  detail  that  yet  higher  com- 
plexity which  results  when  the  several  senses  are  employed 
together.  A  single  extreme  case  will  suffice.  If  we  re- 
member how  a  mineralogist,  in  identifying  a  mass  of  matter 
as  of  a  kind  fitted  for  a  certain  use,  examines  its  crystal- 
line form,  its  colour,  texture,  hardness,  cleavage,  fracture, 
degree  of  transparency,  lustre,  specific  gravity,  taste,  smell, 
fusibility,  magnetic  and  electric  properties,  &c.,  and  is  de- 
cided in  his  conduct  by  all  these  taken  together;  it  will  be 
obvious  that  throughout  the  higher  range  of  cases,  increase 
in  the  speciality  of  the  correspondence  involves  increase  in 
its  complexity. 

§  161.  But,  as  already  hinted,  we  eventually  rise  to  an 
order  of  correspondences  in  which  the  speciality  and  the 
complexity  are  no  longer  co-ordinate.  A  further  advance 
in  speciality  is  achieved  by  a  more  than  proportionate 
advance  in  complexity.    Let  us  look  at  an  example  or  two. 

The  archer  who  points  his  arrow,  not  at  the  object  he 
seeks  to  hit,  but  above  it,  and  who  varies  the  angle  of 
elevation  according  as  the  object  is  far  or  near,  exhibits 
something  more  than  a  special  response  to  special  stimuli; 
for  his  procedure  implies  consciousness  of  the  fact  that  bodies 
projected  through  the  air  descend  towards  the  Earth,  and 
that  the  amount  of  their  descent  has  some  relation  to  the 
distance  traversed.  Besides  a  correspondence  with  certain 
perceived  relations  in  the  environment,  there  is  implied  a 
correspondence  with  the  law  of  certain  other  relations,  not 
then  present  to  the  senses.    Again,  the  engineer  who  erects 


CORRESPONDENCE  AS  INCREASING  IN  COMPLEXITY.  353 

a  suspension-bridge  competent  to  bear  a  specified  strain,  is 
guided  less  bj  his  inspection  and  measurement  of  the  river 
to  be  crossed,  than  by  his  knowledge  of  the  strength  of 
wrought  iron,  of  the  properties  of  the  catenarian  curve,  of 
the  composition  of  forces — his  acquaintance  with  the  uni- 
versal truths  of  number,  geometry,  and  mechanics.  In 
these  cases  the  complexity  of  the  correspondence  is  greatly 
in  excess  of  the  speciality.  To  bring  out  this  fact  by  a 
contrast : — It  might  fairly  be  said  that  the  Indian  fish  which 
catches  insects  flying  over  the  surface  by  hitting  them  with 
jets  of  water,  exhibits  an  adjustment  of  inner  to  outer  rela- 
tions as  special  as  that  shown  by  the  archer;  but  consider- 
ing that  in  the  fish,  nothing  more  is  implied  than  an  auto- 
matic connexion  between  certain  visual  impressions  and 
certain  muscular  contractions,  it  cannot  be  held  that  there 
is  anything  like  the  same  complexity  of  correspondence. 
Similarily,  though  the  strength  of  a  spider's  web  may  be  as 
specially  adjusted  to  the  demands  to  be  made  upon  it,  as  is 
that  of  the  engineer's  suspension-bridge;  yet  there  is  no 
comparison  between  the  two  adjustments  in  respect  of  the 
variety  and  elaborateness  of  the  actions  by  which  they  are 
achieved. 

What  constitutes  this  excess  of  complexity?  It  is  con- 
stituted by  the  addition  of  generalities  to  specialities.  Each 
of  these  higher  correspondences  displaying  what  we  call 
rationality,  implies  an  adjustment  of  inner  relations  not 
simply  to  the  particular  outer  relations  perceived,  but  to 
sundry  general  relations  not  then  perceived,  but  established 
by  previous  experience.  And  as  we  advance  to  corre- 
spondences of  still  greater  complexity,  we  see  that  their 
leading  characteristic  is  the  increasing  number  of  gene- 
ralizations recognized,  and  involved  in  the  process  of  ad- 
justment. Indeed,  the  highest  achievements  of  science,  as 
exemplified  in  astronomy,  show  us  that  an  exact  adapta- 
tion of  the  actions  of  the  organism  to  special  actions  in  the 
environment,  supposes  a  pre-establishment  of  general  re- 


35^  GENERAL  SYNTHESIS. 

latioDS  in  the  organism,  parallel  to  aU  those  general  rela- 
tions in  the  environment  which  these  special  actions  imply. 

§  162.  There  seems  no  place  fitter  than  this,  for  drawing 
attention  to  the  important  fact  that  an  approximately-con- 
stant ratio  is  maintained  between  the  impressibilities  and 
the  aoti/vitdes  of  the  organism,  in  so  far  as  their  complexity 
is  concerned.  In  the  lowest  animal  types  we  see  a  touch 
followed  by  a  withdrawal  of  the  part  touched — a  single 
stimulus  followed  by  a  single  motion.  Gradually  as  we 
ascend,  abilities  to  receive  increasingly-complicated  impres- 
sions, and  to  perform  increasingly-complicated  actions  pre- 
sent themselves.  And  the  truth  here  to  be  observed  is, 
that  the  heterogeneity  of  the  stimuli  which  can  be  appre- 
ciated is  in  general  proportionate  to  the  heterogeneity  of 
the  changes  which  can  be  displayed. 

Note,  first,  that  survival  of  the  fittest  ensures  this  con- 
nexion. As  every  advance  consists  in  the  adjustment  of 
some  further  internal  relation  to  some  further  external  rela- 
tion; and  as  the  ability  to  recognize  the  external  relation 
is  useless  unless  there  is  an  ability  to  modify  the  conduct 
appropriately;  it  is  clear  that  for  the  better  preservation  of 
life,  the  passive  and  active  elements  of  the  correspondence 
must  progress  together.  A  power  to  perceive  the  direction 
and  distance  of  an  object  must  be  accompanied  by  a  power 
to  specialize  the  movements;  otherwise  it  can  be  of  no 
service.  The  recognition  of  certain  forms,  colours,  and 
motions,  as  those  of  an  enemy,  will  not  prevent  destruction 
unless  it  is  followed  by  such  quick  acts,  such  doublings, 
such  leaps,  as  the  enemy  may  be  eluded  by.  Discrimination 
shown  in  the  choice  of  materials  for  its  nest,  is  so  much 
faculty  thrown  away  unless  the  bird  has  sufficient  construc- 
tive skill  for  nidification.  It  will  not  profit  the  savage  to 
discover  at  what  seasons  and  what  times  of  the  tide  par- 
ticular fish  are  to  be  caught,  unless  he  has  dexterity  enough 
to  make  and  use  hooks  or  nets  for  catching  them.    Every- 


CORRESPONDENCE  AS  INCREASING  IN  COMPLEXITY.  355 

where  it  must  on  the  average  happen  that  each  additional 
differentiation  of  the  perceptions,  opening  the  way  for  an 
additional  differentiation  of  the  actions,  fails  to  benefit  the 
species,  and  therefore  fails  to  be  established  in  the  species, 
unless  there  goes  along  with  it  an  additional  differentiation 
of  the  actions. 

This  connexion  between  progress  in  the  impressibilities 
and  progress  in  the  activities,  is,  indeed,  otherwise  necessi- 
tated; for  they  so  act  and  react  that  the  advance  of  either 
involves  the  advance  of  both.  The  general  relation  between 
irritability  and  contractility,  which,  in  the  lowest  types  of 
animal  life,  constitute  one  indivisible  phenomenon,  is  a 
relation  which  the  regulative  and  the  operative  divisions  of 
the  organism  maintain  throughout  all  their  complications. 
They  are  co-ordinate  in  their  origin;  they  are  co-ordinate  in 
their  manifestations;  they  are  co-ordinate  in  their  evolution. 

This  truth  becomes  conspicuous  when  we  contemplate  the 
two  functions  under  their  most  general  forms — sensation 
and  motion.  Given  an  organism  with  certain  sensory  and 
motor  faculties,  what  will  happen  from  the  increase  of 
either?  Higher  powers  of  motion  and  locomotion  must 
bring  the  organism  into  relation  with  a  greater  number  of 
objects;  and  must  therefore  multiply  its  impressions. 
Higher  impressibility  must  subject  the  organism  to  more 
frequent  stimuli  to  action ;  and  so  must  multiply  its  motions 
and  locomotions.  Again,  varied  activities  entail  variety 
among  the  relations  in  which  a  creature  puts  itself  towards 
surrounding  things;  and  hence  entail  variety  among  the 
modes  in  which  surrounding  things  affect  it.  Conversely, 
the  more  various  the  impressions  receivable  from  surround- 
ing things,  the  greater  must  be  the  number  of  modifications 
in  the  stimuli  given  to  the  motor  faculties;  and  hence,  the 
greater  must  be  the  tendency  towards  modified  actions  in 
the  motor  faculties.  Thus  the  progress  of  each  is  involved 
with  the  progress  of  the  other,  in  respect  both  of  activity 
and  complexity. 
24 


856  GENERAL  SYNTHESIS. 

This  inevitable  simultaneity  in  the  development  of  the 
directive  and  executive  faculties,  will,  however,  be  most 
clearly  seen  on  analyzing  a  few  cases.  Take  as  one,  the 
ability  to  recognize  direction  in  space.  At  first  this  seems 
to  imply  development  of  the  sensitive  part  of  the  nature 
only:  an  expansion  of  the  retina  sufficiently  great  to  admit 
of  its  components  being  separately  affected  by  images 
falling  on  them.  But  a  little  consideration  shows  that 
something  more  is  required  than  ability  to  perceive  differ- 
ences between  the  positions  of  images  on  the  visual  tract. 
Taken  alone,  these  differences  are  meaningless.  They  come 
to  have  meaning  only  when  they  are  severally  connected  in 
the  organism  with  those  differences  of  motion  required  to 
bring  its  surface  into  contact  with  the  things  seen.  Mere 
ocular  impressions  do  not  of  themselves  give  ideas  of  space. 
Such  ideas  are  products  of  a  growing  experience  which 
proves  that  these  impressions  are  due  to  objects  that  can  be 
touched  by  particular  muscular  adjustments.  Direction, 
therefore,  cannot  be  perceived  until  there  is  a  motor  appa- 
ratus sufficiently  developed  to  effect  specialized  movements. 
Consequently,  the  ability  to  perceive  direction  and  the  ability 
to  take  advantage  of  the  perception,  are  necessarily  connate. 
The  recognitions  of  distances,  of  velocities,  of  bulks,  of 
shapes,  obviously  imply  the  like  conditions.  So,  too,  is  it 
with  the  variations  of  surfaces  indicated  by  lights  and 
shades:  these  variations  have  to  be  disclosed  by  corre- 
sponding variations  in  the  adjustments  of  the  muscles, 
before  lights  and  shades  can  be  interpreted.  No  definite 
idea  of  weight,  as  connected  with  visual  appearances,  can 
be  arrived  at  until  there  is  a  power  of  lifting,  either  by  jaws 
or  limbs.  Nor  can  degrees  of  hardness  and  unlikenesses  of 
texture  be  perceived  in  surrounding  objects,  faster  than  the 
manipulative  organs  are  perfected.  Indeed,  as  these 

last  instances  show  us,  the  inter-dependence  is  even  more 
intimate  than  above  alleged ;  for  besides  being  required  for 
the  interpretation  of  impressions,  muscular  aid  is  required 


CORRESPONDENCE  AS  INCREASING  IN  COMPLEXITY.  357 

even  for  the  reception  of  impressions  in  their  higher  forms. 
Perfect  vision  implies  a  focal  adjustment  of  the  eyes,  an 
adjustment  of  their  axes  to  the  requisite  convergence,  a 
turning  of  them  both  towards  the  object,  sometimes  a  turn- 
ing of  the  head  in  the  same  direction,  and  sometimes  also  a 
turning  of  the  body:  all  which  preparatory  acts  are  per- 
formed by  muscles.  Neither  taste  nor  smell  can  be  acute 
unless  the  muscles  of  the  tongue  and  the  chest  do  their 
parts  in  moving  about  the  food  or  drawing  in  the  air. 
Hearing,  too,  is  imperfect  unless  the  ineTnhrana  tympani  is 
strained  by  its  muscles  so  that  it  vibrates  in  concord  with 
each  successive  sound.  Above  all,  the  perceptions  reached 
through  touch  show  this  dependence  on  the  motor  appa- 
ratus. A  sensitive  skin  is  but  a  small  part  of  the  require- 
ment, as  any  one  may  prove  by  closing  his  eyes  and  apply- 
ing his  bare  arm  or  leg  to  an  unknown  object.  Tactual 
sensations  are  combined  into  ideas  of  extension,  form,  soli- 
dity, only  when  this  sensitive  skin  is  distributed  over  sur- 
faces capable  of  deriving  simultaneous  or  rapidly-succeed> 
ing  sensations  from  different  parts  of  the  things  touched; 
and  these  sensations  must  be  joined  with  those  muscular 
sensations  accompanying  the  simultaneous  and  successive 
adjustments  of  the  sensitive  surfaces.  There  must  be  limbs 
to  effect  the  larger  and  simpler  adjustments,  with  append- 
ages at  the  ends  of  them  to  effect  the  smaller  and  more 
elaborate  ones.  And  only  in  proportion  as  these  motor 
agencies  become  complex,  can  there  be  complexity  in  the 
tactual  perceptions.  But  these  motor  agencies — these  limbs 
and  appendages  with  all  the  muscles  they  are  moved  by,  are 
also  the  locomotive  and  manipulating  organs;  and  the  same 
completeness  of  structure  which  fits  them  to  receive  com- 
pound impressions,  fits  them  to  perform  compound  opera- 
tions. The  evolution  of  the  sensitive  or  directive  apparatus, 
is  thus  inseparable  from  the  evolution  of  the  muscular  or 
executive  apparatus. 


368  GENERAL  SYNTHESIS. 

§  163.  This  all-essential  relationship  must  detain  us 
somewhat  longer.  It  will  be  instructive  to  glance  at  the 
inter-dependence  of  the  recipio-motor  functions  and  the 
dirigo-motor  functions  (§  18)  as  exhibited  in  the  concrete. 
I  refer  to  the  sundry  striking  instances  which  the  animal 
kingdom  presents  of  unusual  sagacity  co-existing  with 
unusual  development  of  organs  which,  by  the  help  of  com- 
plex muscular  arrangements,  give  complex  tactual  im- 
pressions. 

Why  touch,  the  simplest  and  earUest  sense,  should,  in  its 
k^her  forms,  be  more  than  any  other  sense  associated  with 
the  advance  of  intelligence,  will  perhaps  seem  difficult  to 
understand.  The  explanation  lies  in  the  fact  that  tactual 
impressions  are  those  into  which  all  other  impressions  have 
to  be  translated,  before  their  meanings  can  be  known.  If 
we  contemplate  the  general  relation  between  the  organism 
and  surrounding  objects,  we  see  that  before  they  can  affect 
it,  or  it  can  affect  them,  in  any  important  way,  there  must 
be  actual  contact.  Eating,  breathing,  locomotion,  the 
destruction  of  prey,  the  escape  from  enemies,  the  formation 
of  nests  and  burrows,  the  bringing  up  of  young,  all  imply 
mechanical  actions  and  reactions  between  the  animal  and  its 
environment.  The  space-penetrating  faculties  serve  but  as 
guides  to  these  mechanical  actions;  and  the  impressions 
they  receive  are  primarily  used  but  as  symbols  of  tangible 
properties  and  the  relations  among  them.  Hence,  only  as 
fast  as  the  impressions  gained  through  the  skin  and 
muscles  become  varied  and  complex,  can  there  be  a  com- 
plete translation  of  the  varied  and  complex  impressions 
gained  through  the  eyes,  ears,  and  nose.  The  mother 
tongue  must  be  as  copious  as  the  foreign;  otherwise  it 
cannot  render  all  the  foreign  meanings.  And  thus,  as  seen 
in  the  facts  referred  to,  a  highly-elaborated  tactual  appa- 
ratus comes  to  be  the  uniform  accompaniment  of  superior 
intelligence.    But  let  us  look  at  these  facts. 

Each  great  division  of  the  animal  kingdom  supplies  them. 


CORRESPONDENCE  AS  INCREASING  IN  COMPLEXITY.  359 

The  CephxiUypoda^  which  in  sagacity  go  far  beyond  all 
other  MoUusca^  are  structurally  distinguished  from  them 
in  having  several  arms  by  which  they  can  grasp  an  object 
on  all  sides,  at  the  same  time  that  they  apply  it  to  the 
mouth.  Again,  the  crabs,  which  similarly  stand  at  the 
head  of  the  sub-kingdom  ArticvZata  bring  their  claws  and 
foot-jaws  simultaneously  to  bear  on  the  things  they  are 
manipulating.  Merely  glancing  at  these  instances  furnished 
by  the  invertebrate  classes,  let  us  devote  our  attention  to 
those  which  the  vertebrate  classes  furnish. 

It  will  be  admitted  that,  of  all  birds,  parrots  have  the 
greatest  amount  of  intellect.  Well,  if  we  examine  in  what 
they  differ  most  from  their  kindred,  we  find  it  to  be  in 
development  of  the  tactual  organs.  Few  birds  are  able  to 
grasp  and  lift  up  an  object  with  the  one  foot  while  standing 
on  the  other.  The  parrot,  however,  does  this  with  ease. 
In  most  birds  the  upper  mandible  is  scarcely  at  all  move- 
able. In  the  parrot  it  is  moveable  to  a  marked  extent. 
Generally,  birds  have  the  tongue  undeveloped  and  tied 
down  close  on  the  lower  mandible.  But  parrots  have  it 
large,  free,  and  in  constant  employment.  Above  all,  that 
which  the  parrot  grasps  it  can  raise  to  its  beak;  and  so 
can  bring  both  mandibles  and  tongue  to  bear  upon  what  its 
hand  (for  it  is  practically  a  hand)  already  touches  on  several 
sides.  Obviously  no  other  bird  approaches  to  it  in  the 
complexity  of  the  tactual  actions  it  performs  and  the  tactual 
impressions  it  receives. 

Among  mammals  it  is  unquestionable  that  as  a  general 
rule  the  Unguiculata^  or  those  which  have  limbs  terminating 
in  separate  digits,  are  more  intelligent  than  the  TJngulata^ 
or  hoofed  animals.  The  feline  and  canine  tribes  stand 
psychologically  higher  than  cattle,  horses,  sheep,  and  deer. 
Now,  that  feet  furnished  with  several  sensitive  toes  can 
receive  more  complicated  impressions  than  feet  ending  in 
one  or  two  masses  of  horn,  is  manifest.  While,  by  a  hoof, 
only  one  side  of  a  solid  body  can  be  touched  at  once,  the 


360  GENERAL  SYNTHESIS. 

divided  toes  of,  for  example,  a  dog,  can  simultaneously 
touch  the  adjacent  sides  of  a  small  body,  if  not  the  opposite 
sides.  And  when  we  remember  how  those  toed  quadrupeds 
of  higher  types,  which  cannot  grasp  with  their  feet,  can 
nevertheless  use  them  for  holding  down  what  they  are  tear- 
ing or  gnawing,  we  see  that  they  can  recognize  tangible  rela- 
tions of  some  complexity.  Moreover,  when  we  meet  with 
any  marks  of  sagacity  among  hoofed  animals,  as  in  the  horse, 
we  find  that  the  lack  of  sensitive  extremities  is  partly  com- 
pensated for  by  highly  sensitive  and  mobile  lips,  which  have 
considerable  powers  of  prehension.  Here  we  are 

naturally  reminded  of  the  most  remarkable,  and  perhaps  the 
most  conclusive,  instance  of  this  connexion  between  deve- 
lopment of  intelligence  and  development  of  the  tactual 
organs — that  seen  in  the  elephant.  I  say  most  conclusive, 
because  the  elephant  is  markedly  distinguished  from  allied 
tribes  of  mammals,  alike  by  its  proboscis  and  by  its  great 
sagacity.  The  association  between  the  operative  and  regu- 
lative faculties  stand  out  the  more  conspicuously,  from  the 
endowment  of  both  being  exceptional.  On  the  intellect  of 
the  elephant  there  is  no  need  to  dwell:  all  know  its  supe- 
riority. The  powers  of  its  trunk,  however,  must  be  enume- 
rated. Note  first,  its  universality  of  movement  in  respect 
of  direction.  Unlike  limbs,  the  motions  of  which  are  in 
most  mammals  more  or  less  confined  to  the  vertical  plane, 
its  flexibility  gives  it  as  wide  a  range  of  positions  as  the 
human  arm  can  take — wider,  indeed,  than  can  be  taken  by 
a  single  arm;  and  thus  the  elephant  can  ascertain  the 
relations  in  space,  both  of  its  own  members  and  of  sur- 
rounding things,  more  completely  than  all  other  creatures 
save  the  Primates.  Again,  the  trunk  can  grasp  bodies  of 
every  size,  from  a  pea  to  a  tree  stump;  and  by  this 
means  can  perceive  a  far  greater  variety  of  tangible  forms 
than  any  of  the  lower  mammalia.  The  finger-like  projec- 
tion with  which  the  trunk  terminates,  is  affected  by  minor 
variations  of  surface;  and  so,  textures  and  the  details  of 


CORRESPONDENCE  AS  INCREASING  IN  COMPLEXITY.  361 

shape  can  be  made  out,  as  well  as  general  extension.  Its 
ability  to  lay  hold  of  and  to  lift  bodies  of  many  sizes  and 
natures,  opens  the  way  to  a  knowledge  of  weight  as  con- 
nected with  visible  and  tangible  attributes.  The  same 
power  of  prehension,  used  as  it  habitually  is  for  the 
breaking-off  of  branches,  brings  experiences  of  the  tenacity 
and  elasticity  of  matter;  and  when  employed,  as  these 
branches  often  are,  for  driving  away  flies,  the  swinging  of 
them  about  must  yield  impressions  even  of  momentum — 
impressions  which  the  ability  to  throw  small  bodies  (as 
gravel  over  the  back)  must  tend  to  strengthen.  Further, 
the  trunk's  tubular  structure  fits  it  for  many  hydraulic 
experiments,  that  disclose  sundry  mechanical  properties 
of  water  unknown  to  other  quadrupeds;  and  this  same 
peculiarity,  rendering  it  possible  to  send  out  strong 
blasts  of  air  which  produce  motion  in  the  light  bodies 
adjacent,  so  brings  yet  another  class  of  experiences.  Thus, 
the  great  diversity  of  tactual  and  manipulatory  powers 
possessed  by  the  elephant's  proboscis,  is  not  less  remark- 
able than  is  the  creature's  high  sagacity — a  sagacity  which, 
dwelling  in  so  ungainly  a  body,  would  otherwise  be  inex- 
plicable. Passing  to  the  Primates,  we  find  re- 
peated, under  other  forms,  this  same  relation  between 
evolution  of  intellect  and  evolution  of  tactual  appendages. 
Not  more  in  the  contrasts  between  them  and  inferior 
mammals  is  this  seen,  than  in  the  contrasts  between  the 
genera  of  the  Primates  themselves.  The  prehensile  and 
manipulatory  powers  of  the  lower  kinds  are  as  inferior  as 
are  their  mental  powers.  On  ascending  to  the  very 
intelligent  anthropoid  apes,  we  find  the  hands  so  modified 
as  to  admit  of  more  complete  opposition  of  the  thumb  and 
fingers;  the  bones  of  the  forearms  so  articulated  as  to  give 
the  hands  greater  powers  of  rotation;  the  arms  attached 
to  the  body  in  such  a  manner  as  allows  them  increased 
range  of  lateral  movement.  In  all  the  more  developed  of 
the  order,  the  fore-limbs  are  so  constructed  that  an  object 


362  GENERAL  SYNTHESIS, 

can  be  grasped  in  one  hand  while  it  is  being  manipulated 
by  the  other,  or  by  the  lips  and  teeth — can  be  held  at  the 
most  convenient  distance  from  the  eyes — can  be  applied  to 
any  part  of  the  body,  or  any  neighbouring  object.  So 
that  far  more  complex  perceptions  of  size,  shape,  structure, 
texture,  hardness,  weight,  flexibility,  tenacity,  &c.,  and  of 
their  various  combinations,  can  be  reached  by  them  than 
are  accessible  to  creatures  whose  limbs  are  less  elaborately 
constructed. 

How,  in  man,  recvpio-motor  and  dirigo-motor  structures 
and  functions  are  both  still  further  elaborated,  scarcely 
needs  saying.  As  contemplated  from  an  obverse  point  of 
view,  the  connexion  between  them  is  abundantly  exempli- 
fied in  works  on  natural  theology.  All  that  we  need  here 
notice  is  the  extent  to  which,  in  the  human  race,  a  perfect 
tactual  apparatus  subserves  the  highest  processes  of  the 
intellect.  I  do  not  mean  merely  that  the  tangible  attributes 
of  things  have  been  rendered  completely  cognizable  by  the 
complex  and  versatile  adjustment  of  the  human  hands,  and 
that  the  accompanying  manipulative  powers  have  made  pos- 
sible those  populous  societies  in  which  alone  a  wide  intelli- 
gence can  be  evolved.  I  mean  that  the  most  far-reaching 
cognitions,  and  inferences  the  most  remote  from  perception, 
have  their  roots  in  the  definitely-combined  impressions 
which  the  human  hands  can  receive. 

This  inter-dependence  of  the  impressibilities  and  activi- 
ties as  displayed  in  the  course  of  human  progress,  is  so  strik- 
ing and  instructive  as  to  demand  special  attention,  even  at 
the  cost  of  a  further  suspension  of  the  general  argument. 

§  164.  All  developed  science,  consisting  as  it  does  of 
quantitative  prevision — dealing  as  it  does  with  medsv/red 
results,  is  lineally  descended  from  that  simplest  kind  of 
measurement  achieved  by  placing  side  by  side  the  bodies 
held  in  the  hands.  Our  knowledge  of  the  forces  governing 
the  Solar  System  is  expressed  in  terms  that  are  reducible, 


CORRESPONDENCE  AS  INCREASING  IN  COMPLEXITY.  363 

by  an  ultimate  analysis,  to  equal  units  of  linear  extension, 
which  were  originally  fixed  by  the  direct  apposition  of  like 
natural  objects.*  And  the  undeveloped  sciences  that  have 
not  yet  passed  the  stage  of  qualitative  prevision,  depending 
for  their  advance,  as  they  do,  either  on  experiments  re- 
quiring skilful  manipulation  or  on  observations  implying 
dissection  and  other  analogous  procedures,  could  not  have 
reached  this  stage  in  the  absence  of  a  highly-developed 
manual  dexterity. 

But  this  intimate  connexion  between  the  directive  and 
executive  faculties,  is  even  still  more  clearly  to  be  traced 
in  certain  other  phenomena  of  civilization.  This  mutual 
dependence  of  the  regulative  and  operative  powers,  which 
Anaxagoras  had  a  glimpse  of  when  he  uttered  his  hyper- 
bolical saying  that  animals  would  have  been  men  had  they 
had  hands,  is  remarkably  and  conclusively  exemplified  in 
the  reciprocity  of  aid  between  the  Sciences  and  the  Arts. 
It  needs  but  a  little  analysis  to  show  that  under  their 
psychological  aspects.  Sciences  and  Arts  represent  what  in 
their  lowest  forms  we  call  sensory  and  motor  processes. 
The  perceptions  gained  through  sensory  organs  and  the 
actions  performed  by  motor  ones,  respectively  rise,  by  com- 
bination, into  scientific  generalizations  and  manufacturing 
operations.  A  comparison  of  the  extremes  does  not  very 
obviously  show  this;  but  on  looking  at  the  transitions  the 
filiation  becomes  manifest.  It  cannot  be  denied  that  the 
complex  perceptions  of  which  each  sense  is  the  agent, 
together  with  the  still  more  complex  perceptions  reached  by 
co-operation  of  several  senses,  are  forms  of  the  organism's 
impressibility;  nor  that  the  combinations,  more  and  more 
involved,  of  motive,  locomotive,  and  manipulative  powers, 
are  forms  of  the  organism's  activity.  It  cannot  be  denied 
that  out  of  these  complex  perceptions,  woven  into  general 
ideas  still  more  complicated,  finally  arise  the  previsions  of 

•  For  explanation,  see  essay  on  "  The  Genesis  of  Scienoe,' 


364  GENERAL  SYNTHESIS. 

science;  nor  that  all  handicrafts,  and  after  them  the  higher 
processes  of  production,  have  grown  out  of  that  manual 
dexterity  in  which  the  elaboration  of  the  motor  faculty  ter- 
minates. If,  looking  at  the  entire  range  of  phenomena,  we 
seek  out  the  essential  nature  of  the  changes  an  organism 
goes  through  in  adjusting  itself  to  the  environment — if  we 
divide  these  changes,  as  we  must,  into  those  which  external 
objects  impress  on  it,  and  those  by  which  it  appropriately 
modifies  its  relations  to  the  external  objects — if  we  name 
these  respectively,  the  directive  changes  and  the  executive 
changes;  we  see  clearly  that  sensations,  perceptions,  con- 
ceptions, generalizations,  and  all  forms  of  cognition,  come 
under  the  one,  while  contractions,  locomotions,  and  all  kinds 
of  operations,  come  under  the  other;  and  that  Science  and 
Art,  so  far  as  they  are  separable  at  all,  belong,  the  one  to 
the  first  division  and  the  other  to  the  last. 

This  truth  being  recognized,  we  shall  perceive  the  signi- 
ficance of  the  reciprocity  of  services  between  the  Sciences 
and  the  Arts.  Each  great  step  towards  a  knowledge  of 
laws  has  facilitated  men's  operations  on  things;  while 
each  more  successful  operation  on  things  has,  by  its 
results,  facilitated  the  discovery  of  further  laws.  Astro- 
nomy and  agriculture,  geometry  and  the  laying  out  of 
buildings,  mechanics  and  the  weighing  of  commodities — 
these  were  among  the  earliest  relations  of  the  two.  Pre- 
sently geometry,  as  developed  by  artificers,  acted  on  astro- 
nomy; and  astronomy  reacted  to  the  great  advancement  of 
geometry.  Through  the  medium  of  the  scales,  mechanics, 
joined  with  the  science  of  number,  influenced  the  metal- 
lurgic  arts,  gave  definite  alloys,  introduced  metallic  instru- 
ments, and  by  so  doing  advanced  the  accuracy  of  astro- 
nomical and  other  observations,  and  improved  all  those 
processes  of  production  for  which  metallic  tools  are  em- 
ployed. Metallurgy,  too,  by  supplying  plane  and  concave 
mirrors,  initiated  optics;  and  the  first  proposition  in  har- 
monics was  reached  by  the  help  of  strings  and  weights 


CORRESPONDENCE  AS  INCREASING  IN  COMPLEXITY.  365 

which  the  arts  furnished.  As  we  advanced  to  modern  times 
the  connexion  becomes  increasingly  conspicuous.  We  see 
it  in  the  dependence  of  navigation  on  astronomy,  mag- 
netism, and  meteorology;  arid  the  aid  rendered  to  mag- 
netic and  meteorologic  science  by  navigation — in  the 
development  of  geology  by  mining,  quarrying,  and  well- 
sinking;  and  the  guidance  which  geology  now  gives  to  the 
search  for  coal,  metals,  and  water.  The  compounds  and 
elements  with  which  chemistry  deals  were  at  first  brought 
to  light  by  the  arts;  and  the  arts  are  now  all  more  or  less 
dependent  on  chemistry.  There  is  scarcely  an  observation 
now  made  in  science,  but  what  involves  the  use  of  in- 
struments supplied  by  the  arts;  while  there  is  scarcely  an 
art-process  but  what  involves  some  of  the  previsions  of 
science.  This  fact,  that  the  mutual  aid  becomes 

ever  more  active,  further  elucidates  the  general  truth  we 
are  contemplating.  For  as,  when  tracing  upwards  the  direc- 
tive and  executive  faculties,  we  found  that  their  dependence 
on  each  other  grows  continually  greater — that  complete 
visual  and  tactual  perceptions  are  impossible  without  com- 
plex muscular  adjustments,  while  elaborate  actions  require 
the  constant  overseeing  of  the  senses;  so,  among  these  still 
higher  cognitive  and  operative  processes,  we  now  find  a 
reciprocity  such  that  each  further  cognition  implies  elabo- 
rate operative  aid,  and  each  new  operation  implies  sundry 
elaborate  cognitions. 

These  correlations  are  equally  well,  or  even  still  better, 
seen  in  the  objective  appliances  used.  We  may  properly 
say  that  in  its  higher  forms,  the  correspondence  between 
the  organism  and  its  environment  is  effected  by  means  of 
supplementary  senses  and  supplementary  limbs.  All  ob- 
serving instruments,  all  weights,  measures,  scales,  micro- 
meters, verniers,  microscopes,  thermometers,  &c.,  are 
artificial  extensions  of  the  senses;  and  all  levers,  screws, 
hammers,  wedges,  wheels,  lathes,  &c.,  are  artificial  exten- 
sions of  the  limbs.    The  magnifying  glass  adds  but  another 


366  GENERAL  SYNTHESIS. 

lense  to  the  lenses  existing  in  the  eye.  The  crowbar  is  but 
one  more  lever  attached  to  the  series  of  levers  forming  the 
arm  and  hand.  And  the  relationship  which  is  so  obvious  in 
these  first  steps,  holds  throughout.  This  being  perceived,  a 
meaning  becomes  manifest  in  the  fact  that  the  development 
of  these  supplementary  senses  is  dependent  on  the  develop- 
ment of  these  supplementary  limbs,  and  vice  versa.  Accu- 
rate measuring  instruments  imply  accurate  instruments  for 
turning  and  planing;  and  these  cannot  be  made  without 
the  aid  of  previous  measuring  instruments  of  some  accu- 
racy. A  first-rate  astronomical  quadrant  can  be  produced 
only  by  a  first-rate  dividing  engine;  a  first-rate  dividing 
engine  can  be  produced  only  by  first-rate  lathes  and  cutting 
tools;  and  so,  tracing  the  requirements  backwards,  it  be- 
comes obvious  that  only  by  repeated  actions  and  reactions 
on  each  other,  can  directive  and  executive  implements  be 
brought  to  perfection.  Only  by  means  of  artificial  limbs 
can  artificial  senses  be  developed;  and  only  through  arti- 
ficial senses  does  it  become  possible  to  improve  artificial 
limbs. 

Lastly,  it  may  be  remarked  that  not  only  do  the  direc- 
tive and  executive  elements  of  the  correspondence  develop 
hand  in  hand,  but  the  complications  they  reach  have  analo- 
gous characters.  That  union  of  generalities  with  special- 
ities which  we  found  to  distinguish  the  highly-involved  cog- 
nitions of  Science,  is  visible  also  in  the  highly-involved 
operations  of  Art.  Just  as  a  particular  conclusion  in 
Science  is  reached  by  putting  special  data  to  a  general  prin- 
ciple, which  general  principle  concreted  by  other  data  gives 
other  conclusions;  so,  a  particular  art-product  is  obtained 
by  subjecting  to  special  manipulations  the  material  obtained 
by  some  more  general  process,  which  material  subjected  to 
other  manipulations,  yields  other  art-products. 

§  165.  And  now  on  returning  from  this  long  and  elabo- 
rate digression,  bringing  with  us  the  conceptions  arrived  at, 


CORRESPONDENCE  AS  INCREASING  IN  COMPLEXITY.  367 

we  find  that  they  serve  greatly  to  elucidate  the  subject  of 
the  chapter — the  increase  of  the  correspondence  in  com- 
plexity. 

While  tracing  the  inter-dependence  of  impressibilities 
and  activities  as  they  evolve  into  regulative  and  operative 
faculties  of  high  orders,  the  growing  complexity  of  the 
correspondence  has  been  illustrated  in  several  ways.  The 
progressing  heterogeneity  of  the  impressions  received 
through  each  sense  has  shown  it;  and  still  more  the  pro- 
gressing heterogeneity  of  the  combinations  of  impressions 
yielded  by  co-operation  of  the  senses.  The  compounding 
and  re-compounding  of  the  muscular  movements,  alike  of 
each  limb  by  itself  and  of  the  limbs  and  body  together, 
have  further  exemplified  it.  Above  all  it  has  been  shown 
in  the  advance  of  this  reciprocity  between  the  recipio-motoT 
acts  and  the  di/rigo-motor  acts,  which,  becoming  ever 
closer,  becomes  ever  more  involved;  so  that  eventually  a 
single  accurate  perception  implies  complex  muscular  ad- 
justments, and  a  single  exact  operation  implies  the  guidance 
of  complex  perceptions.  In  all  which  it  is  manifest  that,  as 
alleged  at  the  outset,  advance  in  speciality  of  correspon- 
dence is  in  its  higher  forms  achieved  through  advance  in 
complexity  of  correspondence. 

How  this  increase  of  the  correspondence  in  complexity 
which  we  have  followed  up  through  the  higher  animals  to 
Man,  has  been  continuing  during  civilization,  has  just  been 
shown :  the  advance  of  the  Sciences  and  the  Arts  abundantly 
exemplified  it.  One  note-worthy  fact,  however,  remains  to 
be  named.  Human  evolution,  considered  under  this  aspect, 
is  not  adequately  represented  objectively  by  the  developing 
Sciences  and  the  Arts.  It  must  be  looked  at  also  on  its  sub- 
jective side  as  developing  faculty.  While  there  has  been 
advance  in  the  complexity  of  the  cognitions  and  opera- 
tions that  have  been  age  by  age  attained  to,  there  has  been 
advance  in  the  ability  to  receive  complex  cognitions  and 
perform  complex  operations. 


368  GENERAL  SYNTHESIS. 

For  scientific  and  artistic  progress  is  due  not  simply  to 
the  accumulation  of  knowledge  and  of  appliances:  the  im- 
pressibilities and  the  activities  have  themselves  grown  to 
higher  complications.  There  is  evidence  from  various 
quarters  that  the  minds  of  the  inferior  human  races  cannot 
respond  to  relations  of  even  moderate  complexity;  much 
less  to  those  highly-complex  relations  with  which  advanced 
science  deals.  According  to  the  traveller  Lieutenant 
Walpole,  it  is  remarked  of  the  Sandwich  islanders,  by  their 
teachers,  "  that  in  all  the  early  parts  of  their  education, 
they  are  exceedingly  quick,  but  not  in  the  higher  branches, 
that  they  have  excellent  memories,  and  learn  by  rote  with 
wonderful  rapidity,  but  will  not  exercise  their  thinking 
faculties."  That  is  to  say,  they  can  readily  receive  simple 
ideas  but  not  complex  ones.  Again,  of  the  Australians  we 
read  that  "  some  of  them  are  very  quick  at  acquiring  know- 
ledge, but  they  have  no  power  of  combination  or  concentra- 
tion." *  The  reports  of  Hindoo  schools  disclose,  though  in 
a  less  marked  manner,  the  same  fact.  One  of  the  reasons 
assigned  in  the  United  States  for  not  educating  negro 
children  along  with  white  children,  has  been  that  after  a 
certain  age  they  "  do  not  correspondingly  advance  in  learn- 
ing— their  intellects  being  apparently  incapable  of  being 
cultured  beyond  a  particular  point."  And  this  statement, 
which  might  else  be  suspected  of  bias,  agrees  with  that 
made  respecting  the  same  race  in  Africa  by  Sir  Samuel 
Baker,  who  says ; — "  In  childhood  I  believe  the  negro  to  be 
in  advance,  in  intellectual  quickness,  of  the  white  child  of  a 
similar  age,  but  the  mind  does  not  expand — it  promises 
fruit  but  does  not  ripen."  f  So,  too,  of  the  Andaman  chil- 
dren we  read  that  they  "  catch  up  words  readily  and  repeat 
them,  but  seem  incapable  of  connecting  words  with  corre- 
sponding ideas."  ^    Even  the  finest  uncivilized  races  show 

•  See  Proceedings  of  the  Ethnological  Society. 

f  The  Albert  N'yanza.    Vol.  I,  p.  289. 

I  Trans.  Eth.  Soc.    New  Series,  Vol.  IV.  p.  2ia 


CORRESPONDENCE  AS  INCREASING  IN  COMPLEXITY.  369 

US  tlie  like  limitation.  "  Without  genius  for  discovery,  and 
incapable  of  generalizing,"  the  New  Zealanders  "  are  never- 
theless apt  at  acquiring  the  rudiments  of  learning  "  *  *  * 
"  boys  at  ten  years  of  age  are  more  intelligent  than  English 
boys;  but,  as  a  rule,  few  New  Zealanders  could  be  taught  to 
equal  Englishmen  in  their  highest  faculties."  *  In  all  these 
cases,  as  also  in  the  minor  cases  continually  occurring  among 
ourselves  of  inability  to  understand  reasonings  passing  a  cer- 
tain degree  of  abstruseness,  the  interpretation  is  that  the 
intellect  has  not  reached  a  complexity  equal  to  the  com- 
plexity of  the  relations  to  be  perceived.  Not  only  with 
purely  intellectual  cognitions  does  this  hold;  it  holds  also 
with  what  we  distinguish  as  moral  cognitions.  In  the 
Australian  language  there  are  no  words  answering  to 
justice,  sin,  guilt.  Among  most  of  the  lower  races,  acts 
of  generosity  or  mercy  are  incomprehensible.  That  is  to 
say,  the  more  involved  relations  of  human  actions  in  their 
social  bearings  are  not  cognizable.  We  must  therefore 
conclude  that  the  complex  manifestations,  intellectual  and 
moral,  which  distinguish  the  large-brained  European  from 
the  small-brained  savage,  have  been  step  by  step  made  pos- 
sible by  successive  complications  of  faculty. 

Having,  in  the  previous  chapters,  pointed  out  how  greater 
length  of  life  and  higher  degree  of  life  accompany  increased 
speciality  and  increased  generality  of  correspondences,  it  is 
needless  to  dwell  on  the  fact  that  where  both  these  unite  in 
producing  correspondences  of  increased  complexity,  the  like 
result  must  happen.  It  may  be  added,  however,  that  not 
only  is  this  true  of  the  more  complex  intellectual  guidance 
which,  through  the  medium  of  Science,  advances  the  Arts; 
but  it  is  true  of  the  more  complex  emotional  guidance 
which,  by  making  social  order  possible,  contributes  to  the 
greater  individual  safety  that  social  order  brings. 

•  Thompson's  New  Zealand.    VoL  I,  pp.  85-6. 


CHAPTER  IX. 

THE   CO-OEDINATION   OF   CORRESPONDENCES. 

§  166.  Fully  to  comprehend  the  increase  of  the  corre- 
spondence between  the  organism  and  its  environment,  in 
speciality,  in  generality,  and  in  complexity,  it  is  requisite 
to  contemplate  the  facts  under  yet  another  aspect.  We 
must  look  at  the  general  conditions  by  fulfilment  of  which 
these  more  elaborate  adjustments  of  inner  to  outer  rela- 
tions are  made  possible.  The  performance  of  a  compound 
action  in  response  to  a  compound  impression,  implies  some- 
thing more  than  a  susceptibility  to  each  of  the  several 
elements  constituting  the  compound  impression,  and  a 
power  to  effect  each  of  the  several  motions  constituting  the 
compound  action.  It  implies  that  the  constituent  sensa- 
tions and  contractions  shall  be  combined  after  a  particular 
manner — shall  be  co-ordinated;  and  the  perfection  of  the 
correspondence  will  vary  as  the  perfection  of  the  co- 
ordination. 

Let  us  take  first  a  simple  case,  as  that  of  the  actions 

needed  for  escape  from  an  enemy.    When  we  rise  from 

creatures  in  which  the  motion  of  some  conspicuous  adjacent 

object  is  responded  to  by  random  muscular  movements,  to 

creatures  in  which  the  muscular  movements  are  such  as  to 

carry  the  body  a/voa/y  from  the  dangerous  object;  we  rise 

to  an  adjustment  of  at  least  two  joined  relations  in  the 

organism   to   two   joined   relations    in   the    environment. 

870 


THE  CO-ORDINATION  OF  CORRESPONDENCES.      371 

The  strong  visual  impression  produced  by  the  adjacent 
moving  object  being  the  stimulus  to  activity;  then,  that  the 
activity  may  be  of  the  right  kind,  such  modification  of  the 
impression  as  depends  on  the  direction  of  the  body  in  space 
must  be  recognized,  and  the  activity  modified  accordingly. 
The  impression  which  indicates  dangerousness  and  that 
which  indicates  position,  must  together  control  the  motor 
changes;  and  the  control  must  consist  in  so  ordering  their 
respective  amounts  that  the  resulting  motion  may  carry  the 
organism  away  from  the  source  of  danger.  When  distance 
as  well  as  direction  becomes  cognizable,  and  when  the  colour 
and  shape  of  the  object  are  distinguished  as  well  as  its  mass, 
the  stimulus  is  composed  of  a  much  greater  number  of  ele- 
ments, united  after  a  special  manner;  and  the  more  rapid, 
skilful,  and  varied  the  consequent  actions  become,  the  more 
elaborate  and  more  perfect  are  the  implied  combinations 
of  motor  changes.  While  just  as  a  wrong  combination  of 
motor  changes  involves  a  fall  or  other  failure  of  action;  so, 
a  wrong  combination  of  the  separate  stimuli  entails  a  mis- 
taken perception. 

Space  need  not  be  occupied  in  tracing  up  these  simple 
kinds  of  co-ordination.  It  is  obvious  that  throughout  the 
series  of  increasingly-compound  perceptions,  including  even 
the  recognitions  of  localities  by  identification  of  surrounding 
objects,  the  constituents  of  each  perception  co-operate  after 
a  particular  manner;  and  that,  as  especially  seen  in  this 
case  of  localities,  it  is  only  in  virtue  of  a  definite  relation- 
ship among  them  that  a  definite  perception  is  possible.  No 
less  obvious  is  it  that  the  increasingly-complex  actions  by 
which  higher  creatures  achieve  their  ends,  succeed  only  in 
as  far  as  the  muscular  contractions  implied  are  fitly  regu- 
lated in  their  order,  their  amounts,  and  their  modes  of  con- 
junction. 

§  16Y.  Advancing  from  these  cases  in  which  the  directive 
stimuli,  though  heterogenous,  are  made  up  of  elements  that 


872  GENERAL  SYNTHESIS. 

are  simultaneously  present  to  the  senses,  to  the  cases  in 
which  some  of  their  elements  are  present  to  the  senses  and 
some  not,  we  meet  with  a  sensory  co-ordination  of  a  new 
and  higher  order.  And  where  the  responding  motions,  no 
longer  occurring  as  an  inseparable  group,  are  divided  by 
intervals  that  vary  according  to  circumstances,  we  see  a 
parallel  progress  in  motor  co-ordination.  A  creature  which 
when  pursued  runs  to  its  burrow,  supplies  us  with  an  in- 
stance of  the  one;  while  an  instance  of  the  other  occurs 
in  any  process  which,  like  the  building  of  a  nest,  is 
effected  by  instalments  variously  interrupted  by  other  pro- 
cedures. From  the  stage  in  which  a  single  past 
impression  unites  with  many  present  ones  to  compose  a 
special  stimulus,  and  in  which  the  action  completed  at  in- 
tervals is  tolerably  homogeneous  in  character,  the  advance 
is  towards  a  union  of  many  past  impressions  with  present 
ones,  and  towards  a  kind  of  action  increasingly  heteroge- 
neous in  its  instalments,  as  well  as  in  the  manner  of  their 
succession.  In  men's  daily  transactions,  the  complex 
sights,  sounds,  and  muscular  sensations,  serving  for  im- 
mediate guidance,  are  co-ordinated  with  recollections  of  the 
persons,  places,  things,  events,  to  which  those  transactions 
refer;  and  one  who  mistakes  the  hour  at  which  certain 
business  is  to  be  done  with  certain  people  at  a  certain 
office,  shows  us  how  a  failure  arises  from  imperfect  co- 
ordination of  the  past  and  present  impressions  constituting 
the  directive  stimulus.  The  operations  by  which  wheat  is 
sown,  weeded,  reaped,  stacked,  thrashed,  winnowed,  taken 
to  market,  and  sold,  compose  a  series  of  widely-different 
groups  of  actions  (each  consisting  of  many  minor  groups), 
divided  by  dissimilar  and  variable  intervals,  all  combined 
to  achieve  a  single  end;  and  to  achieve  it  they  must  be 
adjusted  in  a  particular  manner.  The  elaborateness  of 
these  advanced  correspondences  in  which  time  past,  time 
present,  and  time  future  are  alike  involved,  and  which  have 
simultaneous  reference  to  sundry  places  in  space,  is  an 


THE  CO-ORDINATION  OF  CORRESPONDENCES.       3^3 

elaborateness  measured  by  tbe  number  of  past  impressions 
compounded  with  present  ones,  and  past  actions  com- 
pounded with  present  ones.  But  the  all-essential  thing  is 
the  definiteness  with  which  the  combination  is  adapted  to 
the  combination  of  external  circumstances — the  goodness 
of  the  co-ordination. 

§  168.  A  still  higher  species  of  co-ordination  growing 
imperceptibly  out  of  the  last,  and  vaguely  seen  even  in  the 
illustrations  just  given,  involves  not  simply  the  union  of 
past  with  present  specialities,  but  the  union  of  generalities 
with  both.  The  perception  received  yesterday  when  the 
barometer  stood  at  "  Fair,"  together  with  the  perception 
received  to-day,  when  it  stands  at  "  Change,"  bring  no  con- 
clusion unless  joined  to  the  generalization  that  a  fall  of  the 
mercurial  column  commonly  indicates  rain.  Nay,  before  a 
true  inference  can  be  drawn  for  to-morrow's  guidance,  these 
data  must  be  joined  with  the  further  generalization,  that 
only  when  the  air  is  charged  with  water  to  a  certain  degree 
is  rain  indicated  by  a  falling  barometer.  In  other  cases,  as 
in  that  of  a  physician  prescribing  for  his  patient,  many 
remembered  observations  of  bygone  symptoms,  many  ob- 
servations of  existing  ones,  and  many  general  truths  serving 
to  interpret  the  changes  that  have  taken  place,  must  enter 
into  that  directive  process  which  terminates  in  an  appro- 
priate course  of  treatment. 

But  the  most  developed  form  of  co-ordination  is  that 
exhibited  by  quantitative  science.  In  this,  not  only  must 
specialities  be  combined  with  generalities  after  a  perfectly 
definite  manner;  but  there  must  be  perfect  definiteness 
in  each  constituent  of  the  combination.  The  perceptions 
by  which  the  data  are  obtained  must  have  their  elements  so 
exactly  co-ordinated  as  to  give  measured  results.  The  laws 
of  dependence  must  be  so  known  that  they  can  be  expressed 
numerically.  And  the  process  by  which,  out  of  data  and 
laws,  the  prevision  is  finally  evolved,  must  have  each  step 


374  GENERAL  SYNTHESIS. 

united  with  preceding  and  succeeding  steps  in  a  mode  that 
is  quite  specific.  An  estimate  of  the  horse-power  required 
to  move  a  given  steam-vessel  at  a  specified  speed,  involves 
these  general  truths: — that  the  resistance  encountered  by 
a  body  moving  through  fluid  varies  as  the  square  of  the 
velocity;  that  the  area  opposed  by  a  vessel  to  the  water 
varies  as  the  squares  of  its  dimensions;  that  the  ton- 
nage varies  as  the  cubes  of  the  dimensions;  with  sundry 
others.  Particular  forces,  weights,  specific  gravities, 
lengths,  breadths,  depths,  have  to  be  combined  with  these 
general  truths,  each  with  each;  and  the  results  have  to  be 
further  combined  after  particular  modes.  K  one  of  the 
generalities  be  applied  to  the  wrong  specialities — if  the 
formula  for  resistance  be  brought  to  bear,  not  on  the  figures 
representing  sectional  area,  but  on  those  representing  ton- 
nage— if  the  data  be  inexact,  or  the  principles  be  misunder- 
stood, or  the  calculation  be  erroneously  performed,  that  is 
— if  there  be  imperfect  co-ordination  of  the  various  mental 
acts  involved;  a  false  conclusion  is  reached:  there  is  a 
failure  of  cognition:  the  internal  relations  are  not  rightly 
adjusted  to  external  ones,  as  is  proved  by  the  result. 

It  will  further  elucidate  both  this  doctrine  of  co-ordina- 
tion and  the  general  doctrine  of  correspondence,  if  we  con- 
sider how,  for  the  perfect  adjustment  of  inner  to  outer 
relations,  there  must  exist  in  the  first,  elements  and  changes 
symbolizing  all  the  essential  elements  and  changes  in  the 
last.  Undeveloped  life  is  led  by  associations  among  some 
of  the  superficial  attributes  of  things.  Developed  life  is 
led  by  associations  among  those  fundamental  attributes  on 
which  the  actions  of  the  things  depend.  There  is  no  in- 
variable connexion  between  a  loud  sound  and  an  adjacent 
enemy;  and  hence,  creatures  in  which  one  of  these  serves 
as  an  index  to  the  other,  are  often  wrong  in  the  adjustments 
of  their  internal  relations  to  external  ones.  But  the  con- 
nexion between  linear  dimensions  and  solid  contents,  or 
between  velocity  and  momentum,  is  constant,  and  therefore 


THE  CO-ORDINATION  OF  CORRESPONDENCES.      375 

affords  infallible  guidance.  Before  this  infallible  guidance 
can  be  had,  however,  all  the  elements  of  the  relation  must 
be  known.  Whenever  a  group  of  inner  relations,  or  cogni- 
tion, is  completely  conformed  to  a  group  of  outer  relations, 
or  phenomenon,  by  a  rational  process — whenever  there  is 
what  we  call  an  v/nderstanding  of  the  phenomenon — the 
composition  of  the  phenomenon  is,  in  a  sense,  paralleled 
by  the  composition  of  the  cognition.  The  law  that  the 
momentum  of  a  moving  body  varies  as  its  velocity  mul- 
tiplied into  its  weight,  cannot  be  known  until  there  exist 
in  the  mind  conceptions  answering  to  momentum,  velocity, 
and  weight;  it  cannot  be  known  until  there  exist  in  the 
mind  ideas  of  time,  space,  and  matter,  without  which  velo- 
city and  momentum  are  inconceivable;  it  cannot  be  known 
until  there  are  processes  of  thought  answering  to  those 
quantitative  connexions  which  "  varies  as  "  and  "  multiplied 
into  "  indicate ;  nay,  the  law  cannot  be  known  until  the 
states  of  consciousness  symbolizing  time  and  space,  are  so 
co-ordinated  as  to  symbolize  velocity;  nor  until  the  states 
of  consciousness  symbolizing  velocity  and  weight  are  so 
co-ordinated  as  to  symbolize  momentum;  nor  until  these 
three  are  again  co-ordinated  according  to  those  laws  of 
relation  implied  by  ''  varies  as  "  and  "  multiplied  into." 
That  is,  every  attribute  necessarily  involved  in  the  pheno- 
menon must  have  its  internal  representative;  and  the 
several  laws  of  dependence  among  these  attributes  must  be 
each  represented  by  some  constant  relation  among  their 
representatives. 

These  facts  bring  out  into  yet  clearer  light,  the  general 
doctrine  variously  presented  in  the  preceding  chapters.  That 
in  these  highest  manifestations  of  Life  produced  by  the  cul- 
ture of  civilization — these  quantitative  previsions  which  im- 
ply such  intense  vital  action  while  they  so  greatly  subserve 
self-preservation  by  facilitating  commerce  and  the  arts — 
there  should  be  this  elaborate  and  complete  co-ordination 
of  inner  relations  to  symbolize  outer  relations,  serves  as  a 


376  GENERAL  SYNTHESIS. 

crowning  illustration  of  the  truths,  that  Life  is  the  main- 
tenance of  a  correspondence  between  the  organism  and  its 
environment,  and  that  the  degree  of  Life  varies  as  the  degree 
of  correspondence.  The  many  proofs  which  have  been 
given  that  the  life  and  the  correspondence  advance  hand  in 
hand,  become  doubly  conclusive  on  finding  that  the  two 
culminate  together. 


CHAPTER  X. 

THE  INTEGRATION   OF   COEKESPONDENCES. 

§  169,  There  is  one  more  point  of  view  from  which,  the 
phenomena  of  Life  must  be  contemplated.  We  have  to 
note  how,  out  of  co-ordination,  there  grows  up  integration. 
Compound  impressions,  as  well  as  the  compound  motions 
guided  by  them,  continually  approach  in  their  apparent 
characters  to  simple  impressions  and  simple  motions.  The 
co-ordinated  elements  of  any  stimulus  or  of  any  act  ever 
tend  towards  union;  and  eventually  become  distinguishable 
from  one  another  only  by  analysis.  Further,  the  connexion 
between  stimulus  and  act  also  becomes  constantly  closer; 
80  that  at  last  they  seem  two  sides  of  the  same  change. 

Only  by  virtue  of  this  law  do  the  higher  kinds  of  corre- 
spondence become  possible.  In  its  absence,  complex  im- 
pressions could  not  generate  complex  actions  with  the 
needful  rapidity;  nor  would  there  be  time  for  that  immense 
multiplicity  of  adjustments  which  developed  life  displays. 
If  the  two  organic  changes  which  constitute  sensation  and 
motion,  did  not,  in  superior  creatures,  follow  with  greater 
rapidity  than  the  withdrawal  of  a  snail  into  its  shell  follows 
the  touch  of  its  horn,  all  those  correspondences  with  the 
environment  which  imply  any  quickness  of  adaptation 
would  be  impracticable.  If  the  period  that  elapses  between 
the  gaze  of  a  young  child  at  a  stranger  and  the  fit  of  crying 

that  follows  (a  period  during  which  the  component  visual 

377 


378  GENERAL  SYNTHESIS. 

impressions  are  being  co-ordinated),  were  habitually  paral- 
leled in  the  perceptions  of  adults — if  compound  cognitions 
were  not  formed,  and  the  appropriate  operations  produced 
by  them,  in  periods  incomparably  briefer,  human  life  would 
cease. 

The  necessity  for  this  progressive  integration  will  be 
most  clearly  understood  if,  regarding  sensations  as  symbols 
and  perception  as  the  interpretation  of  groups  of  symbols, 
we  observe  what  takes  place  with  verbal  symbols  and  the 
meanings  they  convey.  Where  intelligence  is  but  little 
evolved,  a  single  sensation,  as  of  scent,  serves  the  organism 
for  an  index  of  the  combined  attributes  with  which  such 
scent  is  connected;  and  similarly,  in  undeveloped  language 
a  simple  sound  is  used  to  indicate  a  complex  idea.  In 
either  case,  this  system  answers  very  well  within  narrow 
limits.  But  a  large  increase  in  the  number  of  correspon- 
dences requires  another  system.  By  scent,  only  some 
objects  can  be  distinguished:  many  are  scentless.  Simple 
sounds  and  marks  are  too  few  in  number  to  represent 
any  considerable  variety  of  ideas.  Hence,  in  either  case, 
compound  symbols  must  be  used  before  there  can  be  a 
great  multiplication  of  the  correspondences.  Things  that 
are  without  odour,  and  things  that  are  alike  in  odour,  can 
be  divided  into  sub-classes  when  impressions  of  colour  and 
size,  as  well  as  of  scent,  can  be  appreciated.  And  when 
simple  sounds  are  endlessly  modified  by  articulations,  and 
simple  signs  are  replaced  by  composite  signs,  it  becomes 
possible  verbally  to  indicate  an  infinity  of  objects,  acts, 
qualities,  &c.  But  on  what  condition  only  does  this  more 
elaborate  language  become  serviceable?  or,  to  confine  the 
attention  to  one  division  of  it — What  is  required  before 
composite  written  signs  can  supplant  simple  written  signs? 
It  is  required  that  the  constituent  elements  of  each  com- 
posite sign  shall  be  so  efficiently  co-ordinated,  so  rapidly 
united  in  the  act  oi  perception,  so  integrated,  as  to  become 
practically  one.    Had  the  letters  that  make  up  every  word 


THE  INTEGRATION  OP  CORRESPONDENCES.         379 

to  be  separately  identified,  as  the  child  identifies  them  when 
learning  to  read,  the  system  would  be  of  little  or  no  use. 
Able,  though  it  might  be,  to  express  with  precision  all 
verbal  articulations,  it  could  never  compete  with  the  limited 
system  of  simple  signs,  did  it  remain  thus  cumbrous  in  its 
application.  Similarly  with  the  primordial  language  of 
perception.  If  the  several  colours,  size,  shape,  motion, 
direction,  and  distance,  of  an  object,  had  to  be  successively 
identified  by  the  creature  perceiving  it — if  the  object  had 
to  be  spelled  out  in  this  deliberate  fashion;  the  method  of 
recognition  by  combined  sensations  would  yield  in  utility  to 
the  method  of  recognition  by  a  single  sensation.  Universal 
in  its  powers,  it  would  yet  be  too  slow  of  use  to  satisfy 
the  requirements.  In  both  cases,  however,  the  pro- 
gressive integration  of  the  component  correspondences 
removes  this  difficulty,  by  practically  reducing  the  com- 
pound signs  to  simple  ones.  A  word  made  up  of  a  dozen 
letters  comes  eventually  to  be  recognized  as  quickly  as 
a  single  letter.  The  host  of  impressions  involved  in  the 
perception  of  a  carriage,  seemingly  take  no  more  time  to 
receive  and  interpret  than  a  single  sound  or  taste.  And  thus 
there  is  immeasurable  gain  in  the  speciality  of  the  corre- 
spondences, without  loss  in  their  rapidity.  Let  us  glance 
at  the  results. 

§  170.  It  is  needless  to  dwell  on  the  apparent  simul- 
taneity with  which  the  many  visual  sensations  given  us  by 
an  object,  arouse  those  ideas  of  tangible  extension,  of  resist- 
ance, of  texture,  with  which  experience  has  joined  them: 
the  entire  group  of  sensations  and  the  inferences  drawn 
from  them,  seeming  to  constitute  but  a  single  state  of  con- 
sciousness. Nor  is  it  requisite  to  do  more  than  indicate  the 
exceeding  precision  with  which  the  most  complex  assem- 
blages of  these  symbols  are  instantly  distinguished  from 
nearly  identical  assemblages;  as  shown  in  our  ability  to 
recognize  by  a  single  look,  a  particular  person,  and  even  his 


380  GENERAL  SYNTHESIS. 

particular  mental  state.  But  to  convey  a  vivid  idea  of  the 
manner  in  which  this  integration  of  correspondences  sub- 
serves the  perceptions,  it  will  be  well  to  describe  an  experi- 
ment showing  its  extreme  strength  and  rapidity. 

We  judge  of  distance  by  at  least  three  separate  indica- 
tions. When  the  observed  object  is  known  to  us,  the  angle 
it  subtends,  or,  rather,  the  space  which  its  image  covers  on 
the  retina,  aids  in  the  estimate.  The  particular  focal  adjust- 
ments which  the  eyes  undergo  to  obtain  distinct  vision,  and 
which  are  accompanied  by  certain  muscular  sensations,  assist. 
And  the  muscular  sensations  accompanying  due  convergence 
of  the  visual  axes,  supply  a  third  evidence.  In  ordinary 
vision  these  indications  agree.  But  by  that  ingenious  in- 
strument of  Professor  Wheatstone's  invention — the  Pseudo- 
scope — the  last  two  are  made  to  contradict  each  other. 
The  muscular  actions  by  which  the  visual  axes  are  adjusted 
being  the  more  marked,  and  accompanied  by  the  stronger 
sensations,  give  the  preponderating  evidence ;  and  the  result 
is  that  when  looked  at  through  the  Pseudoscope,  convex 
objects  seem  concave  and  concave  objects  seem  convex.  By 
particular  management,  however — that  is,  by  adding  to  the 
evidence  from  focal  adjustment  some  further  evidence — the 
verdict  of  consciousness  may  be  suddenly  reversed.  If, 
after  contemplating  the  inside  of  a  cup  and  wondering  at  its 
apparent  convexity,  the  cup  be  turned  laterally  little  by 
little,  so  that  the  outside  gradually  comes  into  view  and 
the  opening  grows  more  elliptical,  there  presently  arrives  a 
time  when  the  perception  all  at  once  changes,  and  the  cup 
is  seen  under  its  ordinary  aspect.  Now  the  fact  here  to  be 
remarked  as  so  significant,  is  the  impossibility  of  any  inter- 
mediate or  hesitating  judgment.  Notwithstanding  the  con- 
flict of  evidence,  there  is,  save  at  the  moment  of  change, 
a  definite  perception  either  of  concavity  or  of  convexity. 
The  perception  is  not  incomplete  or  obscure,  but  perfectly 
distinct.  The  preponderating  impressions  dragging  with 
them  all  those  other  impressions  which  they  habitually 


THE  INTEGRATION  OP  CORRESPONDENCES.         381 

imply,  produce  the  same  effect  as  though  these  other  im- 
pressions were  actually  received,  instead  of  the  opposite 
ones  being  received.  The  co-ordinated  sensations  have 
become  so  integrated  that  no  considerable  part  of  the 
group  can  be  present  to  consciousness  without  the  whole 
group  being  present. 

With  the  executive  processes  as  well  as  with  the  directive 
processes,  this  integration  takes  place.  A  long-employed 
combination  of  muscular  actions  is  at  last  almost  undecom- 
posable.  The  tricks  of  walk,  of  attitude,  of  manual  actiou, 
which  children  acquire,  and  of  which  it  is  so  difficult  to 
break  them,  furnish  examples.  We  have  another  example 
in  stammering,  which,  commencing  as  it  often  does  with 
imitation,  becomes,  when  once  established,  next  to  incur- 
able. So,  too,  is  it  with  peculiarities  of  handwriting.  The 
motions  of  the  fingers  having  by  years  of  practice  been  co- 
ordinated in  a  particular  manner,  cannot  be  otherwise  co- 
ordinated without  a  degree  of  labour  to  which  few  are  equal. 
Though,  by  moving  them  slowly  and  with  attention,  the 
fingers  may  be  made  to  produce  differently-formed  letters; 
yet,  on  the  attention  being  relaxed  and  the  usual  speed 
resumed,  the  letters  re-acquire  their  old  characters.  Simi- 
larly in  all  handicrafts,  chains  of  perpetually-repeated  mus- 
cular actions,  however  complex,  eventually  approximate  in 
rapidity  and  ease  to  simple  motions;  and,  at  the  same  time, 
cease  to  be  capable  of  modified  adjustment — tend  more  and 
more  to  produce  one  another  automatically — grow  insepa- 
rable— become  integrated. 

Similar  integrations  go  on  between  cognitions  and  the 
operations  guided  by  them.  In  the  child  learning  to  walk, 
or  to  lay  hold  of  a  neighbouring  object,  or  to  pronounce  a 
word,  there  is  a  deliberate  and  conscious  modification  of  the 
motions  in  obedience  to  the  sensations.  But  in  after-years 
the  various  muscular  adjustments  by  which,  from  minute  to 
minute,  the  intentions  are  fulfilled,  follow  the  will  instanta- 
neously and  without  oversight  of  the  intellect.     While 


382  GENERAL  SYNTHESIS. 

absorbed  in  gossip,  the  seamstress  makes  stitch  after  stitch 
by  a  co-ordination  of  sensations  and  actions  that  has  become 
next  to  instinctive.  When  deep  in  thought — "  absent  in 
mind,"  as  the  phrase  is — the  occurrence  of  particular  per- 
ceptions will  often  be  unconsciously  followed  by  the  actions 
appropriate  to  them:  sometimes  with  ludicrous  effect.  The 
start  on  one  side  caused  by  a  loud  noise  close  at  hand,  or 
the  throwing  out  of  the  arms  to  regain  the  balance  after 
having  slipped,  shows  us  how  directive  and  executive  pro- 
cesses, originally  quite  distinct,  come  to  be  so  united  that 
one  follows  the  other  not  only  instantly  and  without  voli- 
tion, but  often  without  the  possibility  of  prevention.  Even 
where  the  impressions  and  motions  are  both  extremely  com- 
plex, the  law  may  be  traced;  witness  the  feats  of  a  skilful 
billiard-player.  In  one  of  his  strokes  we  see  the  relative 
positions  of  the  three  balls  to  one  another,  to  the  cushions, 
and  to  the  pockets,  all  united  into  a  complex  visual  impres- 
sion co-ordinated  with  the  greatest  nicety;  we  see  the  direc- 
tion of  the  cue,  its  adjustment  to  the  ball,  the  strength  of 
its  impact,  and  the  quality  of  its  impact,  all  accurately  modi- 
fied to  suit  the  requirements;  and  we  see  that  by  long  habit 
the  compound  impression  has  been  so  united  with  the  com- 
pound action,  that  the  one  follows  the  other  almost  mecha- 
nically. No  reasoning  or  calculation  is  required ;  or,  indeed, 
is  permissible.  For  it  is  notorious  that  in  games  of  skill, 
any  lengthened  consideration  or  active  interference  on  the 
part  of  the  higher  faculties,  almost  inevitably  causes  a 
failure.  The  direct  guidance  that  has  been  established 
between  the  constituent  sensations  and  constituent  motions, 
must  be  allowed  free  play;  and  success  becomes  sure  in 
proportion  as,  by  constant  co-ordination,  the  combined 
changes  become  practically  one  change. 

In  all  which  we  may  perceive  how  that  automatic  cha- 
racter shown  in  the  simple  correspondences  of  inferior 
creatures,  is  gradually  assumed  by  more  complex  corre- 
spondences— how  that  integration  which  the  reflex  and 


THE  INTEGRATION  OF  CORRESPONDENCES.         383 

purely  instinctive  correspondences  perfectly  exemplify,  is 
partially  exemplified  by  all  higher  correspondences. 

§  171.  N^ot  only  to  the  constituents  of  immediate  percep- 
tion, to  the  elements  of  composite  motion,  and  to  the  com- 
bination of  the  two,  does  this  law  apply;  it  applies  also  to 
the  highest  processes  of  cognition.  The  most  advanced 
conceptions  of  science  display  it  equally  with  the  achieve- 
ments of  manipulatory  skill.  For  making  a  generalization 
is,  in  reality,  integrating  the  various  separate  cognitions 
which  the  generalization  includes — uniting  them  into  a 
single  cognition.  After  there  has  been  a  mental  accumu- 
lation of  facts  presenting  a  certain  community  of  nature 
(remembered  first  as  isolated  facts  and  after  further  expe- 
rience colligated  as  facts  having  some  resemblance),  there 
suddenly,  on  the  occurrence  perhaps  of  some  typical  exam- 
ple, arises  a  cognition  of  the  relation  of  co-existence  or  se- 
quence common  to  the  whole  group:  the  particular  facts, 
before  loosely  aggregated,  all  at  once  crystallize  into  a  gen- 
eral fact — are  integrated.  The  mode  in  which  this 
result  is  brought  about,  is  the  same  in  these  highest  cases  as 
in  the  lowest  cases.  Continuous  repetition  of  experiences  in 
which  any  two  sensations  are  always  joined,  any.  two  mus- 
cular contractions  constantly  performed  together,  or  any 
perception  uniformly  followed  by  a  special  motion,  results 
in  the  greater  or  less  integration  of  the  component  changes; 
and,  similarly,  continuous  repetition  of  those  more  complex 
experiences  which,  though  superficially  unlike,  one  and  all 
present  the  same  fundamental  relation  of  co-existence  or 
sequence,  ultimately  establishes  a  union  in  thought  between 
the  elements  of  this  relation,  and  still-multiplying  expe- 
riences go  on  consolidating  the  union.  It  will  be 
obvious  without  details,  that  the  same  thing  holds  respect- 
ing the  generalization  of  generalizations.  The  integration 
of  correspondences  is  traceable  from  the  simplest  up  to  the 
most  elaborate  of  the  intellectual  processes.     And  in  the 


384  GENERAL  SYNTHESIS. 

last,  as  in  the  first,  the  effect  is  to  simplify  the  directive  and 
executive  actions,  and  so  to  make  practicable  those  adjust- 
ments that  would  else  fail  from  the  too  slow  succession  of 
the  processes  they  involved.  For  as  the  perception  of  a 
complex  object  would  commonly  be  useless  if  the  per- 
cipient had  to  spell  out  the  constituent  sensations;  so,  any 
series  of  compound  experiences  which,  embodied  in  a  gene- 
ralization, afford  valuable  guidance,  would  be  of  little  or  no 
service  if  every  member  of  the  series  had  to  be  separately 
recollected  before  the  guiding  cognition  could  be  formed. 

§  172.  This  gradual  union  of  the  elements  of  any  internal 
change  by  which  the  organism  adapts  its  acts  to  an  external 
co-existence  or  sequence,  has  been,  in  common  with  previous 
traits  of  advancing  correspondence,  abundantly  displayed  in 
the  course  of  human  evolution.  Progress  in  integration  has 
been  a  necessary  accompaniment  of  progress  in  speciality 
and  complexity,  since  without  it  highly  special  and  complex 
correspondences  cannot  be  achieved;  and  hence  in  propor- 
tion as  civilization  has  displayed  the  last  it  must  have  dis- 
played the  first.  The  one  having  been  illustrated  in  detail 
it  is  therefore  needless  to  illustrate  the  other.  Similarly, 
greater  length  and  degree  of  Life,  involved  as  they  are  by 
greater  complexity  and  speciality  of  correspondence,  have 
accompanied  that  greater  integration  which  has  rendered 
these  possible. 


CHAPTER  XL 

THE  COEEESPONDENCES  TS  THEIE  TOTALITT. 

§  173.  Thus  then  we  find  illustrated  in  all  ways  the  truth 
enunciated  at  the  outset,  that  the  connexions  among  vital 
actions  directly  or  indirectly  correspond  with  the  con- 
nexions among  actions  in  the  environment.  That  method 
by  which  we  sought  out  the  fundamental  fact  on  which  to 
base  a  Synthetic  Psychology,  is  justified  by  its  results.  On 
comparing  the  phenomena  of  mental  life  with  the  most 
nearly  allied  phenomena — those  of  bodily  life — and  inquir- 
ing what  is  common  to  both  groups,  a  generalization  was 
disclosed  which  proves  on  examination  to  express  the  essen- 
tial character  of  all  mental  actions.  Regarded  under  every 
variety  of  aspect,  intelligence  is  found  to  consist  in  the 
establishment  of  correspondences  between  relations  in  the 
organism  and  relations  in  the  environment;  and  the  entire 
development  of  intelligence  may  be  formulated  as  the  pro- 
gress of  such  correspondences  in  Space,  in  Time,  in  Speci- 
ality, in  Generality,  in  Complexity. 

As  hinted  more  than  once,  these  several  modes  in  which 
the  advance  of  the  correspondence  displays  itself,  are  but 
80  many  different  aspects  of  one  mode.  The  vast  array  of 
phenomena  which,  for  convenience'  sake,  we  have  con- 
sidered under  distinct  heads,  form  in  reality  one  general, 
continuous,  and  inseparable  evolution.  By  going  on  simul- 
taneously, the  various  orders  of  progress  described  have 

885 


386  GENERAL  SYNTHESIS. 

rendered  one  another  possible.  Every  kind  of  advance  has 
opened  the  way  for  advances  of  other  kinds;  and  these 
again  have  reacted  in  like  manner.  All  have  been  fur- 
thered by  each;  and  each  has  been  furthered  by  all.  Not 
only  is  extension  of  the  correspondence  in  Time,  at  first 
rendered  possible  only  by  its  extension  in  Space;  but  ulti- 
mately, as  in  the  researches  of  astronomers,  the  greatest 
extension  of  the  correspondence  in  Space  is  achieved 
through  its  extension  in  Time.  Not  only  does  progress  of 
the  correspondence  in  Time  and  Space  involve  increase  in 
its  speciality;  but,  eventually,  that  immense  increase  in 
speciality  implied  by  the  making  of  telescopes  and  chrono- 
meters, gives  a  new  progress  to  the  correspondence  in  Time 
and  Space.  On  the  one  hand,  such  greater  complexity  of 
the  correspondence  as  is  shown  by  discriminating  between 
objects  which  have  many  attributes  in  common,  amounts  to 
advance  in  its  speciality;  and,  on  the  other  hand,  advance 
in  speciality  is  that  without  which  greater  complexity  of 
correspondence  cannot  be  reached.  While,  by  the  corre- 
spondence to  higher  generalities,  the  way  is  opened  for 
more  complex  and  more  special  correspondences;  it  is  by 
accumulated  experiences  of  such  more  complex  and  more 
special  correspondences  that  the  correspondence  to  still 
higher  generalities  is  made  possible.  At  both 

extremes  of  the  evolution  this  consensus  among  the  various 
orders  of  correspondence  is  clearly  traceable;  but  the 
further  the  development  advances  the  more  intimate  does 
the  consensus  become.  If  we  consider  the  results  of  im- 
proved vision  in  some  inferior  species,  we  see  that  besides 
bringing  within  view  a  wider  region,  and  so  extending  the 
correspondence  in  Space,  and  besides  giving  earlier  notice 
of  approaching  prey  or  enemies,  and  so  extending  the  corre- 
spondence in  Time ;  it  brings  a  greater  power  of  discrimina- 
ting among  near  objects,  and  so  initiates  correspondences 
of  higher  speciality.  Similarly,  on  observing  what  takes 
place  in  the  man  of  science  who  adjusts  a  further  inner 


THE  CORRESPONDENCES  IN  THEIR  TOTALITY.     387 

relation  to  some  futher  outer  relation — say  the  relation 
between  an  electric  current  and  the  magnetization  of  iron 
— we  see  that  while  the  discovery  is  an  advance  in  speci- 
ality of  correspondence,  it  immediately  leads  to  a  variety 
of  advances  in  all  orders  of  correspondences.  It  makes 
possible  generalities  and  specialities  of  correspondence  to 
the  phenomena  of  terrestrial  magnetism.  Through  the 
galvanometer  it  leads  to  adjustments,  both  general  and 
special,  between  inner  relations  and  the  outer  relations 
subsisting  among  electrical  phenomena  of  various  orders. 
In  the  same  way  it  does  the  same  thing  in  respect  to  an 
immense  range  of  chemical  phenomena.  And  it  similarly 
brings  within  reach  a  vast  series  of  thermal  phenomena. 
Through  the  agency  of  the  electric  telegraph  which  has 
also  grown  out  of  it,  it  makes  possible  hosts  of  special 
correspondences  between  men's  actions  and  the  changes 
occurring  at  remote  points  on  the  Earth's  surface;  it 
enables  astronomers  to  ascertain  the  relative  longitudes  of 
observatories  with  the  greatest  nicety;  and  by  supplying 
them  with  an  improved  means  of  registering  meridional 
transits,  it  gives  better  data  for  calculating  the  distances 
and  motions  of  the  stars,  for  determining  the  structure  of 
our  Sidereal  System,  for  ascertaining  the  motion  of  the  Sun 
through  space.  In  such  among  other  ways  has  this  one 
advance  facilitated  other  advances  of  all  orders  and  in  all 
directions;  and,  in  a  greater  or  less  degree,  the  like  happens 
from  every  advance. 

So  that  from  the  lowest  to  the  highest  forms  of  life,  the 
increasing  adjustment  of  inner  to  outer  relations  is  one 
indivisible  progression.  Just  as  out  of  the  homogeneous 
tissue  with  which  every  organism  commences,  there  arises 
by  continuous  differentiation  and  integration,  a  congeries  of 
organs  performing  separate  functions  but  remaining  mutu- 
ally dependent,  or  rather  growing  more  mutually  dependent; 
so,  the  correspondence  between  the  actions  going  on  inside 
of  the  organism  and  those  going  on  outside  of  it,  beginning 
26 


388  GENERAL  SYNTHESIS. 

with  some  simple  homogeneous  correspondence,  gradually 
becomes  differentiated  into  various  orders  of  correspon- 
dences, which,  though  constantly  more  and  more  sub- 
divided, maintain  a  reciprocity  of  aid  that  grows  ever 
greater.  These  two  progressions  are  in  truth  parts  of  the 
same  progression.  Without  dwelling  on  the  fact  that  the 
primordial  tissue  displays  the  several  forms  of  irritability  in 
which  the  senses  originate,  and  that  the  organs  of  sense, 
like  all  other  organs,  arise  by  differentiation  of  this  primor- 
dial tissue — without  dwelling  on  the  fact  that  the  impres- 
sions received  by  these  senses  form  the  raw  materials  of 
intelligence,  which  arises  by  combination  of  them  and  must 
therefore  conform  to  their  law  of  development — without 
dwelling  on  the  fact  that  intelligence  advanceBpoH passu 
with  the  advance  of  the  nervous  system,  and  that  the  nervous 
system  has  the  same  law  of  development  as  the  other  sys- 
tems— without  dwelling  on  these  facts,  it  is  sufficiently 
manifest  that  as  the  progress  of  organization  and  the  pro- 
gress of  correspondence  between  the  organism  and  its  envi- 
ronment, are  but  different  aspects  of  the  evolution  of  Life  in 
general,  they  cannot  fail  to  harmonize.  In  this  organization 
of  experiences  which  constitutes  evolving  Intelligence,  there 
must  be  that  same  continuity,  that  same  sub-division  of 
function,  that  same  mutual  dependence,  and  that  same  ever- 
advancing  consensus^  which  characterize  the  physical  orga- 
nization. 

§  174.  That  Intelligence  has  neither  distinct  grades  nor 
is  constituted  of  faculties  that  are  truly  independent,  but 
that  its  highest  manifestations  are  the  effects  of  a  complica- 
tion that  has  arisen  by  insensible  steps  out  of  the  simplest 
elements,  is  a  conclusion  equally  thrust  upon  us  when  we 
turn  from  the  characteristics  of  the  organism  to  the  charac- 
teristics of  the  environment.  Every  act  of  Intelligence 
being,  in  essence,  an  adjustment  of  inner  to  outer  relations, 
it  results  that  as,  in  the  advance  of  this  adjustment,  the 


THE  CORRESPONDENCES  IN  THEIR  TOTALITY.     389 

outer  relations  increase  in  number,  in  complexity,  in  hete- 
rogeneity, by  degrees  that  cannot  be  marked,  there  can  be 
no  precise  demarkations  between  the  successive  phases  of 
Intelligence.  The  space  through  which  the  correspondence 
gradually  extends,  has  no  definite  boundary  up  to  which  a 
certain  order  of  mind  is  competent  but  beyond  which 
another  order  is  required.  N^o  exact  length  of  time  can  be 
named  as  the  greatest  to  which  the  actions  can  be  adjusted 
by  one  supposed  species  of  guiding  principle.  Among  the 
specialities  of  external  phenomena  it  is  impossible  to  fix  on 
that  which  can  be  reached,  but  not  passed,  by  a  particular 
denomination  of  mental  endowment.  Environing  objects 
and  environing  actions  passing  as  they  do  into  higher  and 
higher  complexities  by  gradations  that  are  insensible,  it  is 
impossible  to  draw  among  them  a  line  up  to  which  some 
alleged  kind  of  intellectual  process  may  go  but  beyond 
which  it  cannot  go. 

Evidently  then,  the  classifications  current  in  our  philoso- 
phies of  the  Mind  can  be  but  superficially  true.  Instinct, 
Reason,  Perception,  Conception,  Memory,  Imagination, 
Will,  &e.,  must  be  either  conventional  groupings  of  the 
correspondences,  or  divisions  among  the  operations  which 
are  instrumental  in  effecting  the  correspondences.  However 
widely  contrasted  they  may  seem,  these  various  modes  of 
Intelligence  cannot  be  anything  else  than  either  particular 
ways  in  which  the  adjustment  of  inner  to  outer  relations  is 
achieved,  or  particular  parts  of  the  process  of  adjustment. 

That  there  are  distinctions  among  the  groups  of  pheno- 
mena thus  named  is  doubtless  true.  But,  when  considered 
in  their  essentials,  it  becomes  manifest  that  some  of  them 
merge  into  one  another  as  branches  into  a  trunk,  and  that 
the  rest  are  but  the  different  constituents  of  which  some 
branch  is  made  up. 

§  1Y5.  Here  a  new  region  of  inquiry  opens  before  us. 
Having   found   that   all   the  phenomena   of  Psychology 


390  GENERAL  SYNTHESIS. 

come  within  this  formula  which  unites  them  with  those  of 
Physiology,  we  have  now  to  see  what  distinguishes  the  one 
group  from  the  other.  We  decided  that  we  should  "  best 
fulfil  the  requirements  of  clear  exposition  by  first  exhibiting 
mental  evolution  as  it  may  be  most  generally  conceived, 
and  subsequently  specializing  the  conception "  (§  130). 
One  of  these  steps  has  been  taken  in  the  preceding  chapters, 
which  have  presented  psychological  truths  under  their 
broadest  aspect  as  biological  truths.  It  remains  to  take 
the  other  step  by  presenting  psychological  truths  under 
their  differential  aspect. 

For,  as  was  pointed  out  in  §§  54,  55,  though  objective 
Psychology,  as  dealing  with  a  certain  order  of  vital 
activities,  comes  within  Biology  considered  as  the  entire 
science  of  Life,  it  nevertheless  constitutes  a  sub-science 
clearly  marked  off  from  the  rest ;  just  in  the  same  way  that 
Chemistry,  although  a  part  of  the  general  science  of  Mole- 
cular Physics,  is  rightly  erected  into  a  separate  sub-science, 
because  it  deals  with  the  re-distributions  of  heterogeneous 
molecules  instead  of  the  re-distributions  of  homogeneous 
molecules. 

That  which  distinguishes  the  science  of  psychical  life 
from  the  science  of  physical  life,  we  found  to  be  the  distinct 
cognizance  which  it  takes  of  phenomena  outside  the  organ- 
ism as  well  as  of  phenomena  inside  the  organism.  We  saw 
that,  passing  beyond  the  question  with  which  Physics  deals 
— What  is  the  connexion  between  two  phenomena  A  and  B 
in  the  environment?  and  passing  beyond  the  question  with 
vhich  Physiology  deals — What  is  the  connexion  between 
two  changes  a  and  h  in  the  organism?  the  question  with 
which  Psychology  deals  is — What  is  the  connexion  between 
these  two  connexions?  How  is  the  relation  a  to  &  in  the 
organism  adjusted  to  the  relation  A  to  B  in  the  environment? 
While  admitting,  or  rather  asserting,  that  Biology  at  large 
tacitly  recognizes  phenomena  in  the  environment  as  implied 
by  phenomena  in  the  organism,  I  pointed  out  that  the 


THE  CORRESPONDENCES  IN  THEIR  TOTALITY.     391 

recognition  is  but  tacit,  and  that  tlie  great  mass  of  biological 
inquiries  are  carried  on  without  reference  to  it;  whereas  in 
Psychology  the  recognition  of  environing  actions  and  rela- 
tions is  avowed  and  all-essential — is  repeated  from  moment 
to  moment — is  a  necessary  component  of  every  proposition. 
The  distinction  then  drawn  in  the  most  general  way,  has 
recently  been  illustrated  in  various  special  ways.  For  while, 
that  we  might  obtain  the  most  comprehensive  conception  of 
psychological  phenomena,  we  returned  to  the  most  general 
point  of  view,  and  have  throughout  the  foregoing  chapters 
looked  at  them  simply  as  vital  phenomena  coming  within 
the  definition  of  Life  as  a  whole;  we  have  met  with  abun- 
dant proof  that  the  truths  of  Psychology  differ  from  the 
truths  of  Physiology  by  taking  for  their  subject-matter  nei- 
ther the  relations  of  inner  acts  nor  the  relations  of  outer  acts, 
but  the  adjustments  of  the  inner  to  the  outer.  On  glancing 
back  over  these  chapters  it  will  be  found  that  in  the  first  two 
of  them,  treating  of  purely  physical  life  as  exemplified  in 
plants  and  in  animals  of  the  very  lowest  types,  the  environ- 
ment was  recognized  in  the  smallest  possible  degree:  only 
that  part  of  it  which  touched  the  organism  had  to  be  taken 
into  account.  But  the  moment  we  rose  to  a  type  of 
creature  which  adjusts  certain  organic  relations  to  rela- 
tions of  which  both  terms  are  not  presented  to  its  surface, 
we  passed  into  adjustments  of  the  psychological  order. 
As  soon  as  there  exists  a  rudimentary  eye  capable  of  re- 
ceiving an  impression  from  a  moving  object  about  to  strike 
the  organism,  and  so  rendering  it  possible  for  the  organism 
to  make  some  adapted  movement,  there  is  shown  the  dawn 
of  actions  we  distinguish  as  intelligent.  As  soon  as  the 
organism,  feebly  sensitive  to  a  jar  or  vibration  propagated 
through  its  medium,  contracts  itself  so  as  to  be  in  less 
danger  from  the  adjacent  source  of  disturbance,  we  perceive 
a  nascent  form  of  the  life  classed  as  psychical.  That  is  to 
say,  whenever  the  correspondences  exhibit  some  extension 
in  Space  or  in  Time,  some  increase  of  Speciality  or  Com- 


392  GENERAL  SYNTHESIS. 

plexitj,  we  find  we  have  crossed  the  boundary  between 
physical  life  and  psychical  life.  In  so  far  as  it  deals  at  all 
with  the  adjustments  of  inner  actions  to  outer  actions, 
Physiology  limits  itself  to  the  few  in  which  the  outer 
actions  are  those  of  agents  in  actual  contact  with  the  or- 
ganism— food,  aerated  medium,  and  things  which  produce 
certain  effects  by  touch  (as  insects  which  fertilize  flowers) ; 
thus  leaving  to  Psychology  all  other  adjustments  of  inner 
to  outer  actions.  So  that,  practically,  the  spheres  of  the 
two  are  as  clearly  divided  as  the  organism  is  divided  from 
its  environment  by  its  limiting  membrane. 

§  176.  Quite  apart,  however,  from  the  considerations 
thus  recalled  and  enforced,  we  see  here  the  need  for  a  more 
specific  and  definite  interpretation  of  that  mental  evolution 
which  the  preceding  chapters  exhibit  in  its  fundamental 
form.  The  presentation  of  Intelligence  as  an  adjustment 
of  inner  to  outer  relations  that  gradually  extends  in  Space 
and  Time,  that  becomes  increasingly  special  and  complex, 
and  that  has  its  elements  ever  more  precisely  co-ordinated 
and  more  completely  integrated,  leaves  us  with  a  con- 
ception which  obviously  requires  further  development. 
The  various  degrees  and  modes  of  Intelligence  known  as 
Instinct,  Memory,  Reason,  Emotion,  Will,  and  the  rest, 
must  be  translated  in  terms  of  this  conception.  If,  as  above 
alleged,  the  several  grades  of  Mind  and  its  component 
faculties,  are  phases  of  the  correspondence  and  factors  in 
the  correspondence,  they  can  be  interpreted  as  such;  and 
to  complete  the  argument  it  is  needful  that  they  should  be 
so  interpreted. 

We  have  now,  then,  to  enter  upon  another  department  of 
our  subject.  Closing  here  the  General  Synthesis,  and  car- 
rying with  us  the  fundamental  truth  evolved  by  it,  it  remains 
to  found  upon  that  fundamental  truth  a  Special  Synthesis. 


PART  IV, 


SPECIAL   SYNTHESIS. 


CHAPTER  I. 

THE   NATUBE   OF   INTELLIGENCE.* 

§  177.  The  two  great  classes  of  vital  actions  called  Physio- 
logy and  Psychology  are  broadly  distinguished  in  this,  that 
while  the  one  includes  both  simultaneous  and  successive 
changes  the  other  includes  successive  changes  only.  The 
phenomena  forming  the  subject-matter  of  Physiology  pre- 
sent themselves  as  an  immense  number  of  different  series 
bound  up  together.  Those  forming  the  subject-matter  of 
Psychology  present  themselves  as  but  a  single  series.  A 
glance  at  the  many  continuous  actions  constituting  the  life 
of  the  body  at  large,  shows  that  they  are  synchronous — that 
digestion,  circulation,  respiration,  excretion,  secretion,  &c., 
in  all  their  many  sub-divisions,  are  going  on  at  one  time  in 
mutual  dependence.  And  the  briefest  introspection  makes 
it  clear  that  the  actions  constituting  thought  occur,  not  to- 
gether, but  one  after  another. 

"No  impassable  chasm  between  them  is  thus  constituted 
however.  Even  were  the  highest  psychical  life  absolutely 
distinguished  from  physical  life  in  the  way  alleged,  which 

•  This  chapter  and  all  its  successors  composing  Part  IV.,  remain  in  sub- 
stance the  same  as  in  the  original  edition.  The  numerous  changes  of 
expression,  omissions  of  superfluous  passages,  and  occasional  additions  of 
explanatory  sentences,  have  been  such  only  as  conduce  to  the  clearer  pre- 
sentation of  the  doctrines  set  forth — the  doctrines  themselves  being  un- 
changed.   I  name  this  for  a  reason  sufficiently  indicated  in  the  preface. 

895 


396  SPECIAL  SYNTHESIS. 

we  shall  presently  see  reason  to  doubt,  it  would  still  be  true 
that  psychical  life  in  its  lower  phases  is  not  thus  dis- 
tinguished :  the  distinction  arises  only  in  the  course  of  vital 
progression.  That  gradual  differentiation  and  integration, 
seen  alike  in  the  evolution  of  organic  structures  and  in  the 
evolution  of  the  correspondence  between  their  actions  and 
actions  in  the  environment,  is  also  seen  in  the  separation  of 
this  correspondence  into  its  two  great  orders.  While  through 
it  have  resulted  the  various  subordinate  divisions  of  the 
correspondence,  through  it  also  has  resulted  this  funda- 
mental division.    We  will  look  at  a  few  of  the  facts. 

Passing  over  the  small  animals  moved  by  cilia,  in  which 
the  independence  of  the  many  irritations  and  motions  simul- 
taneously going  on  is  manifest — passing  over  the  Zoophytes, 
in  which  moderate  local  stimulations  produce  local  contrac- 
tions without  affecting  the  organism  as  a  whole — passing 
over  these  creatures  devoid  of  nervous  systems,  let  us  con- 
sider what  happens  when  the  nervous  system  has  attained 
some  development.  In  such  so-called  RadAata  as 

the  Star-fish,  each  of  the  several  like  divisions  composing  the 
body  "  is  connected  with  a  ganglionic  centre,  that  seems  to 
be  subservient  to  the  functions  of  its  own  division  alone,  and 
to  have  little  communication  with,  or  dependence  upon,  the 
remainder,"  *  The  result  is  that  what  elementary  psychical 
changes  the  creature  manifests,  take  place  simultaneously  in 
different  parts  of  its  body :  each  part  separately  responding 
to  the  impressions  made  on  it.  And  hence  the  fact  that 
for  a  length  of  time  after  being  divided  from  one  another, 
the  rays  severally  continue  to  exhibit  their  ordinary 
actions.  In  the  Articulata,  specially  fitted  by  their 

structure  for  showing  it,  this  dispersion  of  the  psychical  life 
is  well  brought  out  by  experiment.  "  The  Mcmtia  rdigiosa 
customarily  places  itself  in  a  curious  position,  especially  when 

•  Carpenter's  Principles  of  Comparative  Physiology.    Fourth  edition, 
p.  654. 


THE  NATURE  OF  INTELLIGENCE.  397 

threatened  or  attacked,  resting  upon  its  two  posterior  pairs 
of  legs,  and  elevating  its  thorax  with  the  anterior  pair,  which 
are  armed  with  powerful  claws :  now  if  the  anterior  segment 
of  the  thorax,  with  its  attached  members,  be  removed,  the 
posterior  part  of  the  body  will  still  remain  balanced  upon  the 
four  legs  which  belong  to  it,  resisting  any  attempts  to 
overthrow  it,  recovering  its  position  when  disturbed,  and 
performing  the  same  agitated  movements  of  the  wings  and 
elytra  as  when  the  unmutilated  insect  is  irritated;  on  the 
other  hand,  the  detached  portion  of  the  thorax,  which  con- 
tains a  ganglion,  will,  when  separated  from  the  head,  set  in 
motion  its  long  arms,  and  impress  their  hooks  on  the  fingers 
which  hold  it. — If  the  head  of  a  Centipede  be  cut-off,  whilst 
it  is  in  motion,  the  body  will  continue  to  move  onwards  by 
the  action  of  the  legs;  and  the  same  will  take  place  in  the 
separate  parts,  if  the  body  be  divided  into  several  distinct 
portions.  *  *  *  *  If  the  body  be  opposed  in  its  progress 
by  an  obstacle  of  not  more  than  half  of  its  own  height,  it 
mounts  over  it,  and  moves  directly  onwards,  as  in  its  natural 
state ;  but  if  the  obstacle  be  equal  to  its  own  height,  its  pro- 
gress is  arrested,  and  the  cut  extremity  of  the  body  remains 
forced  up  against  the  opposing  substance,  tJie  legs  still  con- 
tinuing to  Tnove."  *  All  which  facts  imply  that  even  in  ani- 
mals of  this  comparatively-advanced  organization,  both  or- 
ders of  vital  changes  are  simultaneous  and  successive:  the 
differentiation  of  the  psychical  from  the  physical  life  is  but 
slight.  Even  among  Yertebrata  of  high  types,  this 

differentiation  is  by  no  means  complete.  Many  of  the  actions 
are  partly  voluntary,  partly  automatic ;  and  may  be  performed 
with  various  degrees  of  consciousness,  or  without  conscious- 
ness. This  is  implied  by  the  fact  that  sensations  can  be  re- 
ceived, and  compound  movements  performed,  in  the  absence 
of  the  great  nervous  centres.  Experiments  on  decapitated 
frogs  yield  clear  proof  that  actions  of  considerable  complexity 

•  Carpenter's  Principles  of  Comparative  Physiology,  p.  665. 


898  SPECIAL  SYNTHESIS. 

may  be  efficiently  executed  without  theaid  of  the  brain  (§22). 
The  vivisections  of  Longet,  Vulpian,  and  others,  show  that 
mammals  continue  to  feel  and  retain  certain  of  their  locomo- 
tive powers,  when  both  cerebrum  and  cerebellum  have  been 
removed;  and  that  birds  similarly  deprived  of  these  great 
cephalic  ganglia  can  still  walk  about,  fly,  and  even  pick  up 
food.  Nay,  there  are  cases  on  record  of  infants  that  have  for 
days  continued  to  breathe,  cry,  suck,  and  go  through  various 
movements,  although  bom  without  either  cerebrum  or  cere- 
bellum. Apart  from  evidence  of  this  kind,  the  per- 
sonal experiences  of  every  adult  demonstrate  to  him  that 
there  are  many  actions  belonging  to  the  psychical  division, 
which  either  may  or  may  not  enter  into  the  mental  current. 
The  motion  of  the  legs  is  necessarily  accompanied  by 
various  muscular  and  tactual  changes.  These,  together  with 
the  state  we  call  volition,  may  be  distinctly  present  to  con- 
sciousness— may  be  thought  of  as  by  a  child  learning  to 
walk;  or  they  may,  as  in  ordinary  walking,  be  left  almost 
wholly  out  of  consciousness.  The  processes  we  perform 
while  eating  display  a  similar  relation.  The  several  acts  by 
which  each  morsel  is  selected,  cut,  prepared,  and  carried  to 
the  mouth,  may  perhaps  be  held  to  enter  into  the  current 
of  our  thoughts;  though  in  general,  and  especially  during 
conversation,  they  obtrude  themselves  on  consciousness 
very  slightly.  But  many  of  the  impressions  and  motions 
involved  are  next  to  unconscious.  The  tactual  feelings 
which  the  knife-handle  gives,  the  contractions  by  which  it 
is  grasped,  and  the  muscular  changes  which  the  arms  are 
every  moment  undergoing,  scarcely  at  all  occupy  the  atten- 
tion. So  that  out  of  a  great  number  of  psychical  or  qucm- 
psychical  actions  going  on  in  the  organism,  only  a  part  are 
woven  into  the  thread  of  consciousness;  while  the  others 
form  one  or  more  distinct  strands  which,  as  it  were,  occa- 
sionally inosculate  with  the  thread  of  consciousness.* 

*  I  find  that  there  may  sometimes  be  detected  as  many  as  five  simulta- 
neous series  of  nervous  changes,  which  in  various  degrees  rise  into  con* 


THE  NATURE  OF  INTELLIGENCE.  899 

So  that  only  by  gradual  differentiation  have  the  actions 
constituting  psychical  life  become  specially  successive,  in- 
stead of  simultaneous  and  successive;  and  the  distinction 
is  not  even  now  complete.  In  the  lowest  types  each  part 
of  the  organism,  while  it  performs  by  and  for  itself  all  other 
vital  functions,  also  responds  by  and  for  itself  to  external 
stimuli;  and  the  psychical  changes,  or  what  foreshadow 
them,  are  both  simultaneous  and  successive  to  as  great  an 
extent  as  the  physical  changes.  When  a  nervous  system 
makes  its  appearance,  these  incipiently-psychical  changes 
become  slightly  co-ordinated — have  their  various  strands 
connected.  As  the  nervous  system  develops  and  integrates, 
the  twisting  of  these  various  strands  of  changes  into  one 
thread  of  changes  grows  more  decided.  But  to  the  last 
their  union  remains  imperfect.  The  vital  actions  consti- 
tuting the  subject-matter  of  Psychology,  while  distinguished 
from  other  vital  actions  by  their  tendency  to  assume  the 
form  of  a  single  series,  never  absolutely  attain  that  form. 

§  1Y8.  This  distinction  between  the  psychical  and  the 
physical  life  will  be  most  clearly  understood,  if  we  consider 
the  mode  in  which  it  first  appears  and  the  leading  stages  of 
its  progress. 

Throughout  the  homogeneous  tissue  of  which  the  lowest 
creatures  consist,  there  is  complete  community  of  actions. 
The  vital  processes  go  on  simultaneously  in  many  places 
alike.  These  primordial  organisms,  if  organisms  they  can 
be  called,  exhibit  no  differentiations  of  structure  or  func- 
tion; and  thus  the  two  great  divisions  of  life,  equally  with 
the  subdivisions  of  each,  are,  in  the  beginning,  one. 

sciousness  so  far  that  we  cannot  call  any  of  them  absolutely  unconscious. 
When  walking,  there  is  the  locomotive  series ;  there  may  be,  under  cer- 
tain circumstances,  a  tactual  series ;  there  is  very  often  (in  myself  at  least) 
an  auditory  series,  constituting  some  melody  or  fragment  of  a  melody 
which  haunts  me ;  and  there  is  the  visual  series ;  all  of  which,  subordinate 
to  the  dominant  consciousness  formed  by  some  train  of  reflection,  are 
continually  crossing  it  and  weaving  themselves  into  it. 


400  SPECIAL  SYNTHESIS. 

The  first  great  differentiation  established  is  that  between 
the  inner  and  outer  tissues — the  substances  of  the  body  and 
its  limiting  membrane.  The  parts  of  the  original  proto- 
plasm are  subject  to  but  a  single  contrast  of  conditipns — 
that  between  contact  with  one  another,  and  contact  with  the 
environment.  The  external  portions  are  bathed  by  the 
surrounding  medium;  the  internal  portions  are  not.  And 
in  response  to  this  primary  unlikeness  of  conditions,  there 
eventually  arise  unlikenesses  of  structure  and  function. 
That  which  is  permanently  outermost  takes  on  the  modified 
form  of  vital  action  which  its  circumstances  demand.  That 
which  is  permanently  innermost  similarly  assumes  a  more 
specialized  order  of  activity  {Prim,,  of  Bio.,  §  287). 

The  division  of  labour  thus  commenced  may  be  con- 
sidered as  at  first  physiological  only.  In  virtue  of  its 
position,  the  surface  necessarily  monopolizes  the  duties  of 
absorption — the  taking  in  of  water  and  nutriment  and 
oxygen;  while  to  the  included  mass  remain  such  duties  as 
its  inclusion  permits.  And  when,  by  involution  of  the 
surface,  a  stomach  is  formed,  the  change  implies  a  further 
separation  of  duties,  such  that  nutrition  is  chiefly  confined 
to  one  part  of  the  limiting  membrane  and  aeration  to 
another.  But  the  advance  is  not  an  advance  in  the  physio- 
logical division  of  labour  solely.  It  is  at  the  same  time 
an  advance  towards  the  separation  of  psychical  actions  from 
physical  ones;  and  is  even  a  first  step  towards  bringing 
psychical  actions  into  serial  order.  Necessarily  assuming 
the  vital  offices  entailed  by  its  externality,  the  skin  also 
assumes  the  office  of  receiving  all  those  impressions  which 
form  the  raw  material  of  intelligence.  The  mechanical 
and  other  changes  going  on  in  the  environment,  can  be 
responded  to  by  the  organism  only  when  it  is  affected  by 
them;  and  any  change  they  work  in  it  must  be  proxi- 
mately experienced  by  its  surface.  The  skin,  then,  being 
the  part  immediately  subject  to  the  various  kinds  of  exter- 
nal stimuli,  necessarily  becomes  the  part  in  which  psychical 


THE  NATURE  OF  INTELLIGENCE.  401 

changes  are  originated.  As  contrasted  witli  the  contained 
substance,  it  comes  to  be  more  especially  concerned  in  that 
adjustment  of  inner  to  outer  relations  whicli  constitutes 
intelligence.  But  now  mark  the  implication.    The 

changes  constituting  the  physical  life  continue  to  go 
on  simultaneously  throughout  the  entire  mass.  Those 
which  foreshadow  the  psychical  life  are,  in  an  increasing 
degree,  localized  on  the  outside  of  the  mass — belong  to  its 
outside  primarily  and  affect  some  other  parts  secondarily. 
Speaking  generally,  therefore,  we  may  say  that  while  the 
physical  changes  are  being  everywhere  initiated  throughout 
a  8olid^  .the  psychical  ones,  or  rather  those  out  of  which 
psychical  ones  arise,  admit  of  being  initiated  only  on  a 
surface.  Hence,  even  by  this  primary  differentiation  the 
incipient  psychical  life  comes  to  be  distinguished  from  the 
purely  physical  life,  by  the  diminished  quantity  of  simul- 
taneous changes  it  includes. 

Subsequent  differentiations  have  like  natures  and  results. 
This  sensitiveness  which  forms  the  basis  of  psychical  life, 
is  in  the  beginning  diffused  uniformly  over  the  whole 
surface;  but  it  presently  becomes  in  some  degree  concen- 
trated. Though,  generally,  all  parts  of  the  skin  remain 
impressible  by  touch,  yet  certain  parts,  having  positions 
which  expose  them  to  frequent  tactual  impressions,  become 
more  susceptible  than  the  rest;  and  in  these  parts  most 
of  the  sensations  arise.  That  is  to  say,  the  epi-peripheral 
changes  forming  the  raw  material  of  intelligence,  by  being 
restricted  in  the  area  of  their  occurrence,  have  the  charac- 
teristic of  simultaneity  further  limited;  and  the  more 
highly  developed  the  tactual  apparatus  the  more  marked 
is  the  limitation. 

Still  greater  is  this  limitation  rendered  by  the  evolution 
of  special  senses.  The  olfactory  and  gustatory  sensations 
are  localized  in  smaller  tracts  than  is  the  sensation  of 
touch;  and  each  of  these  tracts  is  little,  if  at  all,  capable 
of  undergoing  more  than  one  change  at  a  time.    Visual  and 


402  SPECIAL  SYNTHESIS. 

auditory  impressions  are  receivable  only  within  yet  narrower 
areas;  and  even  the  two  areas  susceptible  of  each  become 
functionally  one.  The  ears  are  simultaneously  affected  by 
the  same  sounds;  and  in  the  highest  creatures  the  eyes,  being 
so  placed  as  to  converge  their  axes  on  the  same  object,  yield 
to  consciousness  what  seems  to  be  one  image.  Nay,  even 
within  each  group  of  visual  feelings  concentration  is  mani- 
fest. The  greatest  sensitiveness  of  the  retina  is  confined  to 
a  minute  spot;  and  the  feelings  initiated  in  this  spot  domi- 
nate over  the  others  in  consciousness.  If  we  add  that  when 
the  most  advanced  intelligence  is  reached,  the  sensations 
arising  in  the  nose  and  the  palate  are  but  occasional,  while 
those  arising  in  the  eyes  and  ears  are  perpetual;  it  will  be 
seen  to  what  extremely  small  portions  of  the  organism  the 
changes  which  form  the  chief  raw  materials  of  intelligence 
are  ultimately  confined. 

Continued  differentiation  and  integration,  thus  concen- 
trating the  actions  out  of  which  psychical  life  is  evolved,  first 
on  the  surface  of  the  organism,  afterwards  on  certain  regions 
of  that  surface,  afterwards  on  those  most  specialized  parts  of 
it  constituting  the  organs  of  the  higher  senses,  and  finally  in 
minute  parts  of  these  parts,  necessarily  render  the  psychical 
life  more  and  more  distinct  from  the  physical  life  by 
bringing  its  changes  more  and  more  into  serial  order.  We 
have  nothing  to  do  with  the  progressive  development  of 
the  nervous  system,  and  the  actions  that  are  carried  on 
throughout  its  mass.  These  internal  actions  are  initiated 
by  the  external  ones  to  which  the  senses  are  subject. 
And  just  in  proportion  as  the  external  ones  tend  towards 
the  serial  form,  the  consequent  internal  ones  do  the 
same. 

§  179.  This  growing  seriality  in  the  psychical  changes  is, 
indeed,  necessitated  by  advance  of  the  correspondence.  In 
other  words,  the  advance  of  the  correspondence,  the  de- 
velopment of  consciousness,  and  the  increasing  tendency 


THE  NATURE  OP  INTELLIGENCE.  403 

towards  a  linear  order  in  the  psychical  changes,  are  different 
aspects  of  the  same  progression. 

For  how  only  can  the  constituent  changes  of  any  complex 
correspondence  be  co-ordinated?  Those  abilities  which  an 
intelligent  creature  possesses,  of  recognizing  diverse  ex- 
ternal objects  and  of  adjusting  its  actions  to  composite  phe- 
nomena of  various  kinds,  imply  a  power  of  combining  many 
separate  impressions.  These  separate  impressions  are  re- 
ceived by  the  senses — by  different  parts  of  the  body.  If 
they  go  no  further  than  the  places  at  which  they  are  received, 
they  are  useless.  Or  if  only  some  of  them  are  brought  into 
relation  with  one  another,  they  are  useless.  That  an  effectual 
adjustment  may  be  made,  they  must  be  all  brought  into  rela- 
tion with  one  another.  But  this  implies  some  centre  of  com- 
munication common  to  them  all,  through  which  they  sever- 
ally pass;  and  as  they  cannot  pass  through  it  simultaneously, 
they  must  pass  through  it  in  succession.  So  that  as  the 
external  phenomena  responded  to  become  greater  in  number 
and  more  complicated  in  kind,  the  variety  and  rapidity  of 
the  changes  to  which  this  common  centre  of  communication 
is  subject  must  increase — there  must  result  an  unbroken 
series  of  these  nervous  changes,  the  subjective  face  of  which 
is  what  we  call  a  coherent  consciousness. 

Of  course  I  do  not  mean  that  material  actions  thus  be- 
come mental  actions.  As  was  said  in  §§  41 — 51,  62,  63, 
"  no  effort  enables  us  to  assimilate  "  Mind  and  Motion.  I 
am  merely  showing  Siparalldism  between  a  certain  physical 
evolution  and  the  correlative  psychical  evolution. 

§  180.  That  mental  phenomena  constitute  a  series  is  a 
doctrine  of  old  standing,  and  one  the  general  truth  of  which 
none  call  in  question.  As  we  have  seen,  however,  it  is  to  be 
understood  in  a  qualified  sense.  When  the  facts  are  con- 
templated objectively,  it  becomes  manifest  that  though  the 
changes  constituting  intelligence  approach  to  a  single  suc- 
cession, they  do  not  absolutely  form  one — that  there  are 
27 


404  SPECIAL  SYNTHESIS. 

constantly  being  performed  actions  of  an  intelligent  kind 
which  are  not  present  to  consciousness — and  that,  through 
the  many  gradations  between  completely -conscious  actions 
and  completely-unconscious  ones,  the  psychical  changes 
merge  into  those  which  we  distinguish  as  physical.  When 
we  consider  the  facts  subjectively — when  we  interrogate 
consciousness,  we  find  that  though  the  general  seriality  of 
the  changes  is  obvious,  there  are  many  experiences  which 
make  us  hesitate  to  assert  complete  seriality.  Let  us  ex- 
amine one. 

The  visual  impressions  we  receive  from  moment  to 
moment,  though  ordinarily  regarded  as  single  states,  are  in 
reality  multiple  ones;  and  it  becomes  a  perplexing  question 
how  far  each  of  these  can  be  considered  a  member  of  a  linear 
series  of  changes.  Besides  the  particular  thing  to  which  the 
eyes  are  directed,  many  other  things  are  partially  seen;  and 
no  clear  separation  can  be  made  among  the  degrees  of 
definiteness  with  which  they  are  presented  to  conscious- 
ness. Only  one  point  of  the  object  looked  at  is  perceived 
with  perfect  distinctness.  Yet  it  cannot  be  said  that 
consciousness  is  entirely  occupied  with  this  one  point; 
for  the  object  as  a  whole  may  be  identified  by  the 
single  glance  directed  to  this  one  point.  Obviously  our 
consciousness  of  things  within  the  visible  area,  becomes 
smaller  as  they  become  more  remote  from  the  centre  to 
which  the  axes  of  the  eyes  converge.  Obviously  there 
is  no  particular  distance  from  this  centre  at  which  we 
can  say  that  consciousness  ceases.  And  thus  there  would 
seem  to  be  a  great  number  of  nascent  consciousnesses 
of  different  intensities  existing  at  the  same  moment.  Only 
by  a  certain  license,  then,  can  the  internal  change  pro- 
duced by  a  visual  impression  be  called  single.  Strictly 
speaking,  it  is  a  multitude  of  simultaneous  changes  bound 
together.  Still  more  conspicuous  becomes  the 

qualification  with  which  we  must  accept  the  doctrine  that 
psychical  changes  are  distinguished  by  their  seriality,  when, 


THE  NATURE  OF  INTELLIGENCE.  406 

from  the  state  of  consciousness  produced  by  a  visual  im- 
pression, we  go  on  to  observe  the  state  of  consciousness 
known  as  the  resulting  perception.  The  various  distances, 
solidities,  structures,  (fee,  which  appear  to  be  immediately 
given  in  the  impression,  being  really  known  by  inference, 
severally  imply  many  changes;  and  these  changes  are 
practically  synchronous  with  those  constituting  the  im- 
pression itself,  since  the  positions  and  natures  of  the  ob- 
jects are  recognized  in  the  instant  of  perception.  So  that 
beyond  that  complexity  of  a  visual  consciousness  due  to  the 
many  co-existing  feelings  and  relations  it  includes,  there  is 
a  further  complexity  caused  by  the  many  represented  feel- 
ings and  relations,  which  are  so  closely  united  with  the 
presented  ones  as  seemingly  to  form  with  them  one  con- 
sciousness. 

^Nevertheless,  the  doctrine  that  psychical  life  is  distin- 
guished from  physical  life  by  consisting  of  successive 
changes  only,  instead  of  successive  and  simultaneous 
changes,  may  be  shown  from  the  very  facts  here  cited. 
For  though  a  visual  impression  makes  us  nascently  con- 
scious of  many  things,  yet  there  is  always  some  one 
thing  of  which  we  are  more  conscious  than  of  the  rest. 
And  when  we  so  look  at  this  one  thing  as  to  perceive  it  in 
the  true  sense  of  the  word — to  know  it  as  such  or  such,  we 
are  almost  exclusively  occupied  with  it.  Though  the  images 
of  other  things  are  all  the  while  being  impressed  on  the 
retina,  and  are  producing  changes  there,  yet  these  are 
not  appreciated  internally — are  scarcely  more  than  physi- 
cal changes — do  not  undergo  that  co-ordination  with  others 
which  constitutes  them  psychical  changes.  And  this -fact, 
that  in  proportion  as  any  object  seen  is  distinctly  thought 
of,  the  other  objects  within  view  cease  to  be  thought  of, 
shows  clearly  how  consciousness  becomes  more  definitely 
serial  as  it  rises  to  a  higher  form.  In  brief,  we  may  say 
that  while  the  outer  strands  of  changes  which  constitute 
the  thread  of  consciousness,  are  indefinite  and  loosely  adhe* 


406  SPECIAL  SYNTHESIS. 

rent,  there  is  always  an  internal  closely-twisted  series  of 
changes,  forming  what  we  may  consider  as  consciousness 
proper. 

Psychical  changes  therefore,  if  not  absolutely  distin- 
guished from  physical  changes  by  their  seriality,  are  rela- 
tively so  distinguished;  and  in  proportion  as  they  assume 
that  most  developed  form  constituting  rationality  they  co- 
here into  a  seemingly-single  succession  of  states.  Though 
these  states  are  physiologically  composite,  and  were  once 
psychologically  composite,  yet,  to  the  extent  that  they  have 
become  consolidated  elements  of  thought  they  may  rightly 
be  regarded  as  severally  simple. 

§  181.  Such,  then,  is  the  outcome  of  our  examination. 
Gradually  differentiated  from  the  lower  order  of  changes 
constituting  bodily  life,  this  higher  order  of  changes  con- 
stituting mental  life  assumes  a  decidedly-serial  arrange- 
ment in  proportion  as  intelligence  advances.  Though  this 
serial  arrangement  never  becomes  complete,  yet  in  the 
human  consciousness  it  approaches  completeness;  and 
the  highest  processes  of  this  consciousness  are  possible 
only  on  condition  that  its  successive  states,  compound  as 
ihej  may  be  in  nature,  shall  comport  themselves  as  practi- 
cally elementary.  The  fact  that  every  proposition  ex- 
presses a  relation,  and  that  every  relation  subsists  between 
two  terms,  of  itself  proves  that  distinct  thought  necessi- 
tates serial  arrangement  of  its  components. 

A  succession  of  changes  being  thus  the  subject-matter 
of  Psychology,  it  is  the  business  of  Psychology  to  deter- 
mine the  law  of  their  succession.  That  they  follow  one 
another  in  a  particular  way,  the  existence  of  Intelligence 
itself  testifies.    The  problem  is  to  explain  their  order. 


CHAPTER  n. 


THE  LAW   OF   INTELLIGENCE. 


§  182.  All  Life,  whether  physical  or  psychical,  being  the 
combination  of  changes  in  correspondence  with  external  co- 
existences and  sequences,  it  results  that  if  the  changes 
constituting  psychical  life  occur  in  succession,  the  law  of 
their  succession  must  be  the  law  of  their  correspond- 
ence. 

An  adequate  statement  of  this  law  is  by  no  means  easy  to 
find.  Did  the  phenomena  in  the  environment  form,  like  the 
phenomena  of  consciousness,  a  succession,  there  would  be 
no  difficulty.  The  entire  fact  would  be  expressed  by  saying 
that  the  internal  succession  parallels  the  external  succession. 
But  the  environment  contains  many  successions  of  pheno- 
mena, going  on  simultaneously.  Further,  there  are  found 
in  it  a  great  variety  of  phenomena  which  are  not  successive 
at  all,  but  co-existent.  Again,  it  is  unlimited,  and  the  phe- 
nomena it  includes  are  not  only  innumerable,  but  insensibly 
pass  into  a  relative  non-existence  as  the  distance  from  the 
organism  increases.  Once  more,  the  environment,  relatively 
considered,  is  ever  varying  as  the  organism  moves  from 
place  to  place.  How  then  can  the  succession  of  psychical 
changes  be  in  any  way  formulated?  How  is  it  possible  to 
express  the  law  of  a  single  series  of  internal  phenomena  in 
terms  of  its  correspondence  with  an  infinity  of  external 

phenomena,  both  serial  and  non-serial,  mixed  in  the  most 

407 


408  SPECIAL  SYNTHESIS. 

heterogeneous  manner,  and  presented  to  the  moving  or- 
ganism in  fortuitous  combinations  never  twice  alike? 

Were  it  not  that  the  inner  relations  must  correspond  with 
the  outer  ones;  and  that  therefore  the  order  of  states  of 
consciousness  must  be  in  some  way  expressible  in  terms  of 
the  external  order;  we  might  despair  of  finding  any  general 
law  of  psychical  changes.  Even  as  it  is,  we  may  be  certain 
that  no  general  law  can  apply  to  extended  portions  of  the 
series  of  changes.  Mainly  dependent  as  these  must  be,  on 
the  assemblages  of  things  by  which  the  organism  is  en- 
vironed, and  on  the  new  assemblages  perpetually  disclosed 
by  its  movements,  they  can  be  no  more  formulated  than 
these  assemblages  can  be  formulated.  Evidently,  it  is 
in  the  immediately-connected  changes,  and  small  groups 
of  changes,  rather  than  in  the  longer  concatenations  of 
changes,  that  a  law  is  to  be  sought. 

§  183.  A  correspondence  between  the  internal  order  and 
the  external  order,  implies  that  the  relation  between  any 
two  states  of  consciousness  corresponds  with  the  relation 
between  the  two  things  producing  them.  How  corresponds? 
The  two  states  of  consciousness  occur  in  succession;  and 
all  successions  are  alike  in  so  far  as  they  are  simply  succes- 
sions. In  what,  then,  can  the  correspondence  consist?  In 
this,  that  the  jpersistence  of  the  connexion  between  the  states 
of  consciousness  is  proportionate  to  the  persistence  of  the 
connexion  between  the  agencies  to  which  they  answer.  The 
relations  between  external  objects,  attributes,  acts,  are 
of  all  grades,  from  the  necessary  to  the  fortuitous.  The 
relations  between  the  answering  states  of  consciousness  must 
similarly  be  of  all  grades,  from  the  necessary  to  the  for- 
tuitous. When  any  state  a  occurs,  the  tendency  of  some 
other  state  d  to  follow  it,  must  be  strong  or  weak  according 
to  the  degree  of  persistence  with  which  A  and  D  (the  objects 
or  attributes  that  produce  a  and  d)  occur  together  in  the 
environment.    If,  in  the  environment,  there  is  a  more  per- 


THE  LAW  OF  INTELLIGENCE.  409 

sistent  occurrence  of  A  with  B  than  of  A  with  D;  then,  the 
maintenance  of  the  correspondence  implies  that  when  a 
arises  in  consciousness,  &  shall  follow  rather  than  d.  These 
are  manifest  requisites.  If  the  strengths  of  the  connexions 
between  the  internal  states  are  not  proportionate  to  the 
persistences  of  the  relations  between  the  answering  external 
agents,  there  will  be  a  failure  of  the  correspondence — the 
inner  order  will  disagree  with  the  outer  order. 

A  due  understanding  of  the  matter  may  best  be  obtained 
by  examining  the  several  objections  to  this  general  statement. 

§  184.  The  acts  of  animals  exhibit  countless  failures  of 
the  internal  order  to  parallel  the  external  order.  In  the 
moth  which  flies  at  a  candle-flame,  there  exists  no  relation 
of  psychical  states  answering  to  the  relation  between  light 
and  heat  in  the  environment.  The  connexion  between  the 
odour  of  a  flower  and  the  contained  honey,  is  duly  responded 
to  by  sequent  actions  in  the  moth;  as  is  also  the  connexion 
between  a  certain  change  in  the  field  of  view  and  the  ap- 
proach of  a  living  body.  But  there  is  no  internal  adjust- 
ment by  which,  after  the  visual  impression  produced  by  a 
flame,  anything  like  the  feeling  of  a  burn  is  suggested;  and 
hence  the  creature's  death.  Again,  the  birds  which  on  un- 
inhabited islands  allow  explorers  to  approach  close  to  them, 
manifestly  lack  that  co-ordination  of  psychical  changes  by 
which  the  birds  of  our  woods  and  moors  are  led  to  fly 
the  sportsman.  Externally  there  co-exists  with  particular 
appearances,  a  destructive  activity;  but  internally,  the  state 
of  consciousness  roused  by  these  appearances  is  not  followed 
by  any  state  of  consciousness  representing  a  destructive 
activity:  and  a  risk  of  being  killed  is  the  consequence.  A 
child's  perception  of  some  brightly-coloured  berry  does  not 
excite  an  idea  of  pain,  or  of  the  word  "  poison,"  but  more 
probably  some  idea  of  a  pleasant  taste ;  and  should  injurious 
chemical  properties  co-exist  with  these  attractive  visible 
ones,  the  child's  life  may  be  endangered.    But  in  all  cases 


410  SPECIAL  SYNTHESIS. 

of  this  kind  what  is  the  implication?  Do  we  not  speak  of 
the  injuries  suffered  as  resulting  from  lack  of  sagacity?  or 
as  evincing  ignorance?  And  is  it  not  a  corollary  that,  as 
non-conformity  of  the  inner  to  the  outer  order  is  want  of 
intelligence,  conformity  of  the  inner  to  the  outer  order  is 
that  in  which  intelligence  consists? 

A  few  instances  in  which  the  failure  of  the  correspondence 
is  not  total  but  partial,  will  enforce  this  conclusion.  The 
dog  that  comes  on  hearing  his  name  called,  usually  does  so 
expecting  to  find  his  master  or  some  member  of  the  family ; 
but  if,  as  occasionally  happens,  his  name  is  called  by  a 
stranger,  the  sequence  in  his  states  of  consciousness  is  not 
adapted  to  the  external  facts:  he  makes  a  mistake.  Among 
the  Australian  savages,  who  mostly  meet  with  violent  deaths, 
it  is  the  belief  that  any  one  who  dies  without  apparent  cause 
has  been  killed  by  an  unseen  foe;  and  a  stranger  who  hap- 
pens to  be  found  near  at  hand  is  liable  to  be  sacrificed  as  the 
supposed  assassin.  Here,  though  the  mental  connexion 
between  death  and  enmity  very  generally  agrees  with  the 
connexion  in  the  environment,  it  by  no  means  uniformly  does 
so.  The  earlier  chemists,  by  a  large  number  of  experiences 
respecting  the  combinations  of  acids  and  bases,  were  led  to 
think  of  substances  that  neutralized  bases  as  substances 
having  sour  tastes;  but  this  relation  of  ideas,  though  very 
generally  in  harmony  with  external  relations,  is  not  always  so. 

What,  now,  do  we  say  of  cases  like  these,  in  which  the 
inner  order  does  not  completely  answer  to  the  outer  order? 
We  say  that  they  imply  a  low  degree  of  intellect,  or  a 
limited  experience,  or  a  but  partial  enlightenment.  And  the 
disappearance  of  these  discrepancies  between  thoughts  and 
facts  we  speak  of  as  an  advance  in  intelligence. 

§  185.  "  But  how  does  this  conception  include  co-exist- 
ences? "  it  may  be  asked.  "  In  so  far  as  the  environment 
presents  motions  and  changes,  there  is  no  difficulty  in 
understanding   the   law   of   intelligence   to   be,   that   the 


THE  LAW  OP  INTELLIGENCE.  411 

strength  of  the  tendency  which  the  antecedent  of  any 
psychical  change  has  to  be  followed  by  its  consequent,  is 
proportionate  to  the  persistence  of  the  union  between  the 
external  things  they  symbolize.  But  when  this  union  is  not 
between  successive  things  but  between  simultaneous  things 
— not  a  union  in  Time  but  a  union  in  Space,  it  is  less  easy 
to  see  how  the  parallelism  between  the  inner  and  the  outer 
order  can  result  from  fulfilment  of  this  law.  The  con- 
nexion between  two  states  of  consciousness  occurring  in 
succession,  can  very  well  represent  the  connexion  between 
two  external  phenomena  occurring  in  succession.  But  if  it 
can  do  this,  it  cannot  also  represent  the  connexion  between 
two  external  phenomena  not  occurring  in  succession." 

The  full  reply  to  this  objection  will  be  contained  by  im- 
plication in  a  future  chapter,  on  "  The  Relations  of  Co- 
existence and  Non-Coexistence."  Here  it  must  suffice  to 
say  that  the  relation  of  co-existence  is  distinguished  from 
the  relation  of  sequence  by  the  readiness  of  its  terms  to 
follow  one  another  through  consciousness  in  either  order, 
with  equal  facility  and  vividness;  that  the  consciousness  of 
it  arises  when,  in  passing  backwards  and  forwards  from  one 
term  to  the  other,  the  sequences  being  similarly  unresisting 
cancel  one  another;  and  that  thus  it  consists  of  a  duplica- 
tion in  consciousness,  made  up  of  a  sequence  and  its  inver- 
sion. Such  being  the  nature  of  the  relation  of  co-existence, 
subjectively  considered,  the  law  of  intelligence  as  above 
formulated  applies  to  it  no  less  than  to  the  relation  of 
sequence.  If  two  phenomena,  A  and  B,  habitually  co- 
exist in  the  environment,  then,  when  the  phenomenon  A 
is  presented  to  the  senses,  the  produced  state  of  conscious- 
ness a,  is  immediately  succeeded  by  the  state  &,  represent- 
ing the  phenomenon  B.  The  process  of  thought  does  not 
end  here,  however:  if  it  did,  the  external  relation  would 
be  known  as  a  sequence.  But  the  phenomenon  B,  in  the 
environment,  being  as  much  the  antecedent  of  A  as  A  is  of 
B  (neither  of  them  being  antecedent  or  consequent,  except 


412  SPECIAL  SYNTHESIS. 

in  the  order  of  our  experience  of  them),  it  results  that  the 
state  b  having  been  induced,  the  law  involves  that  it  shall 
be  followed  by  the  state  a.  The  state  a,  again  induces  the 
state  &,  and  is  itself  once  more  re-induced;  and  so  on  as 
long  as  the  relation  remains  the  object  of  thought.  Let  us 
take  a  case.  If  the  outlines  and  colours  of  a  body  are  pre- 
sented, the  resulting  consciousness  is  instantly  followed  by 
the  consciousness  of  something  resistant;  and  conversely, 
if,  in  the  dark,  a  body  is  touched,  the  resulting  conscious- 
ness is  instantly  followed  by  the  consciousness  of  something 
extended.  But  in  neither  case  is  this  all.  "When  the  idea 
of  extension  has  been  suggested  that  of  resistance  does  not 
finally  disappear;  nor  when  the  idea  of  resistance  has  been 
suggested  does  that  of  extension  finally  disappear.  Both 
continue  to  be  thought  of,  as  it  would  seem,  almost  simul- 
taneously. And  since  the  two  terms  of  the  relation 
cannot  be  known  in  absolutely  the  same  state  of  conscious- 
ness; since  further,  the  persistent  consciousness  of  them 
cannot  be  one  state  of  consciousness,  which  is  equivalent 
to  no  consciousness;  it  follows  that  the  apparently-inces- 
sant presentation  of  both  is  really  a  rapid  alternation — an 
alternation  so  rapid  as  to  produce  the  effect  of  continuity; 
just  as  the  alternating  impressions  to  which  the  retina  is 
subjected  by  the  pictures  on  the  opposite  sides  of  a  revolv- 
ing thaumatrope,  cause  a  consciousness  of  the  two  pictures 
as  fused  into  one.  Indeed,  as  this  illustration  suggests,  it 
is  in  virtue  of  the  law  of  intelligence  as  above  formulated, 
that  the  relation  of  co-existence  becomes  cognizable.  For 
this  rapidity  with  which  two  states  of  consciousness  answer- 
ing to  two  co-existent  phenomena,  continually  reproduce 
each  other,  itself  exemplifies  the  extreme  cohesion  of  those 
internal  states  which  correspond  to  extremely-coherent  ex- 
ternal phenomena.  And  it  is  in  consequence  of  this  ex- 
treme cohesion,  with  the  quick  alternation  involved  by  it, 
that  the  two  phenomena  are  presented  apparently  together, 
and  the  idea  of  co-existence  generated. 


THE  LAW  OF  INTELLIGENCE.  413 

Where,  as  in  most  cases,  there  are  not  two  co-existent 
phenomena  but  a  group,  this  same  law  implies  cohesion  of 
many  different  states  of  consciousness,  which  similarly  pro- 
duce and  re-produce  one  another  in  all  orders;  and  such  an 
irregularly-varied  presentation  and  re-presentation  of  com- 
bined properties  is  just  what  we  know  takes  place.  Even 
more  apparent  becomes  the  conformity  of  the  facts  to  the 
law  on  remembering,  that  among  the  clustered  states  of 
consciousness  those  which  answer  to  invariably-coexistent 
phenomena,  as  resistance  and  extension,  continue  reproduc- 
ing each  other  during  the  whole  perception,  forming,  as  it 
were,  the  basis  of  it;  whereas  the  several  other  states  of 
consciousness  answering  to  the  special  qualities- of  the  object 
(qualities  not  invariably  co-existing  with  resistance  and  ex- 
tension) do  not  remain  thus  persistent,  but  appear,  and 
disappear,  and  reappear  in  consciousness,  with  degrees  of 
frequency  varying  according  to  the  constancy  of  the  answer- 
ing qualities. 

§  186.  A  fact  seemingly  incongruous  with  the  generaliza- 
tion is,  that  a  great  proportion  of  mental  changes  arise  in  a 
way  which  is  in  one  sense  fortuitous.  !N^oises  heard  through 
the  open  window  traverse  consciousness  in  a  totally-irregu- 
lar manner.  When  walking  along  the  streets,  the  pas- 
sing people  and  vehicles  produce  internal  changes  of  which 
the  succession  is  indeterminate.  External  objects,  attri- 
butes, acts,  being  infinitely  varied  in  their  combinations, 
every  observer  is  subject  to  changing  assemblages  of  im- 
pressions between  which  no  law  of  connexion  can  be  traced. 
Hence,  to  a  large  part  of  the  successive  changes  that  conr 
stitute  intelligence,  the  formula  above  given  must  be  in- 
applicable. 

This  difficulty  will  disappear  on  consideration.  The 
alleged  law  of  intelligence  is  that  the  strength  of  the 
tendency  which  the  antecedent  of  any  psychical  change  has 
to  call  up  its  consequent,  is  proportionate  to  the  persistence 


414  SPECIAL  SYNTHESIS. 

of  the  union  between  the  external  things  they  symbolize. 
Thus  far,  we  have  considered  this  law  with  reference  to 
those  connexions  in  consciousness  which  correspond  to 
established  or  habitual  connexions  in  the  environment. 
Here  the  connexions  in  the  environment  to  which  the 
connexions  in  consciousness  correspond,  are  accidental  ones. 
A  fortuitous  relation  in  the  environment  is  paralleled  by  a 
fortuitous  relation  in  thought  Two  adjacent  mental  im- 
pressions answer  to  two  phenomena  that  are  by  chance 
adjacent  in  Space  or  Time.  Thus  far  the  law  manifestly 
applies  as  before:  the  internal  order  conforms  to  the 
external  order.  But  how,  it  may  be  asked,  can  the  ten- 
dency of  the  antecedent  state  of  consciousness  to  be  followed 
by  the  consequent  state,  be  described  as  proporUonate  to 
the  persistence  of  the  union  between  the  external  things 
they  symbolize?  Very  properly.  Suppose  the  relation  in 
the  environment  to  be  that  between  a  certain  person  and 
some  unusual  place  at  which  he  is  met.  This  relation  may 
either  be  considered  generally,  in  connexion  with  our  ex- 
periences at  large;  or  specially,  as  a  particular  experience. 
Generally  considered,  the  relation  is  one  whose  terms  have 
no  persistence  of  union  whatever:  this  person  may  never 
have  been  in  that  place  before  or  since;  and  in  conformity 
with  this  absence  of  persistence  in  the  external  union,  is 
the  absence  of  any  tendency  for  the  idea  of  the  person  and 
the  idea  of  the  place  to  follow  one  another — at  any  rate 
before  he  was  met  there.  Specially  considered,  the  relation 
is  one  that  actually  occurred;  when  it  occurred,  the  union 
between  its  terms  was  absolute;  and  in  conformity  with 
this  temporarily-absolute  union  of  its  terms,  was  the  tem- 
porarily-absolute tendency  of  the  answering  states  of  con- 
sciousness to  follow  one  another.  As,  at  the  moment  it  was 
observed,  the  adjacent  co-existence  of  the  person  and  the 
place  was  as  absolute  as  is  the  co-existence  of  extension  and 
resistance  in  a  solid  mass;  so,  at  the  moment  it  was 
observed,  the  two  states  of  consciousness  produced  by  the 


THE  LAW  OF  INTELLIGENCE.  416 

person  and  the  place  cohered  as  absolutely  as  do  the  con- 
ceptions of  extension  and  resistance. 

Rightly  interpreted  then,  the  law  applies  as  fully  to  the 
fortuitous  relations  presented  in  any  act  of  perception,  as  it 
does  to  the  more  or  less  habitual  relations  which  experience 
estabHshes  among  ideas. 

§  187.  In  the  succession  of  psychical  changes  there 
doubtless  occur  many  combinations  which  are  not  easily 
explicable.  Thus,  on  the  case  last  instanced  it  may  be 
remarked,  that  though  before  a  certain  person  has  been 
met  in  a  certain  place,  there  exists  no  tendency  for  the 
states  of  consciousness  answering  to  the  person  and  the. 
place  to  occur  together;  yet  afterwards,  the  tendency  for 
one  of  the  states  to  call  up  the  other  is  often  so  decided 
that  it  shows  itself  repeatedly.  Here  then  a  more  per- 
sistent relation  seems  to  be  established  between  the  states 
of  consciousness  than  exists  between  the  corresponding 
phenomena.  Sometimes,  indeed,  the  exceptional 

character  of  the  external  relation  becomes  the  very  cause  of 
tenacity  in  the  internal  relation.  The  more  astonishing  the 
event — the  more  utterly  it  is  at  variance  with  the  ordinary 
course  of  things,  the  stronger  becomes  the  cohesion  be- 
tween the  answering  states  of  consciousness.  Whence  it 
would  appear  that,  occasionally,  psychical  changes  conform 
to  a  law  the  reverse  of  that  enunciated.  Again, 

it  may  be  asked  how,  if  the  law  is  as  alleged,  can  con- 
sciousness ever  escape  out  of  certain  indissolubly-related 
states  when  once  it  gets  into  them?  If,  for  instance,  the 
necessary  co-existence  of  extension  with  a  perceived  resist- 
ance, is  known  through  the  rapid  alternation  of  the  states 
of  consciousness  answering  to  them;  and  if  these  states  are 
as  inseparable  in  the  organism  as  the  phenomena  in  the  en- 
vironment ;  why  should  not  the  two  go  on  reproducing  each 
other  for  ever? 

Fully  to  answer  these  and  all  like  queries,  would  be  to 


416  SPECIAL  SYNTHESIS. 

include  in  tliis  chapter  an  entire  system  of  psychology;  for 
when  all  peculiarities  in  the  succession  of  psychical  changes 
are  explained,  everything  is  explained.  Here,  none  but 
general  replies  can  be  given.  Of  these  the  first 

is,  that,  as  already  said,  the  law  enunciated  is  the  law  of 
intelligence  in  the  abstract ;  not  the  law  of  our  intelligence, 
or  of  any  intelligence  with  which  we  are  acquainted.  It  is 
the  law  to  which  psychical  changes  conform  more  and  more 
as  intelligence  becomes  higher ;  but  which  can  be  perfectly 
conformed  to  only  by  perfect  intelligence.  And  some  of 
the  anomalies  pointed  out  imply  nothing  beyond  imperfec- 
tion in  the  conformity.  But  in  the  majority  of 
cases  it  will  be  found  that  what  seem  to  be  non-conformities 
are  really  conformities  of  a  complex  kind.  It  must  be 
remembered  that  the  succession  of  any  one  state  of  con- 
sciousness after  any  other,  is  due,  not  to  a  single  tendency, 
but  to  a  combination  of  tendencies.  As  in  the  environment 
each  phenomena  stands  related  to  various  surrounding 
phenomena;  as  the  relations  in  which  it  stands  to  these 
are  some  of  them  necessary,  some  very  general,  some  special, 
some  purely  fortuitous;  it  is  a  corollary  from  the  alleged  law 
of  intelligence,  that  each  state  of  consciousness  has  con- 
nexions, more  or  less  close,  with  many  other  states — has  a 
number  of  other  states  simultaneously  tending,  with  various 
degrees  of  strength,  to  arise  after  it.  Consequently,  the 
change  which  actually  takes  place  is  the  resultant  of  many 
tendencies  acting  together.  The  next  state  of  consciousness 
is  produced  by  composition  of  forces.  The  force  with  which 
this  next  state  cohered  to  its  immediate  antecedent,  is  aided 
by  the  forces  with  which  a  group  of  adjacent  states  cohered 
to  it;  and  by  the  union  of  many  small  forces,  a  com- 
pound tendency  may  be  produced  which  overcomes  some 
single  tendency  much  stronger  than  any  one  or  two  of  its 
components.  A  great  physical  law  of  the  external  world 
supplies  us  with  an  analogy.  Simple  as  is  the  principle 
that  every  atom  of  matter  gravitates  towards  every  other 


THE  LAW  OP  INTELLIGENCE.  417 

with  a  force  varying  inversely  as  the  square  of  the  distance, 
yet  we  see  in  the  still  unsolved  "  problem  of  three  bodies," 
how  complex  becomes  the  effect  when  several  forces  conspire 
and  conflict;  and  we  see  how,  when  a  number  of  bodies  are 
acting,  the  course  that  will  be  pursued  by  any  one  of  them 
cannot  be  calculated.  Similarly,  though  the  law  of  attraction 
of  mental  states  is  simple ;  yet  when  the  attractions  of  many 
mental  states  come  into  play — some  uniting,  some  con- 
flicting— it  becomes  next  to  impossible  to  predict  the  result. 
And  just  as  in  the  ascent  of  a  balloon  we  may  meet  with  a 
phenomenon  seemingly  quite  at  variance  with  the  law  of 
gravitation,  though  really  quite  in  harmony  with  it;  so  there 
may  occur  mental  changes  which,  while  they  appear  to  be 
directly  opposed  to  the  law  of  psychical  succession,  are 
nevertheless  fulfilments  of  it. 

Apparent  anomalies  are  thus  reconcilable  with  the  con- 
clusion, that  the  strength  of  the  tendency  which  the  antece- 
dent of  any  psychical  change  has  to  be  followed  by  its 
consequent,  is  proportionate  to  the  persistence  of  the  union 
between  the  external  things  they  symbolize.  Such  is  the 
a  priori  necessity;  and  such  is  the  generalization  reached  « 
posteriori.  Only  in  virtue  of  this  law  can  there  be  that  ad- 
justment of  internal  relations  to  external  relations  which 
constitutes  life,  while  it  makes  possible  the  continuance  of 
life.  And  only  by  supposing  such  a  law  to  exist  can  we 
explain  the  facts,  that  relations  which  are  absolute  in  the 
environment  are  absolute  in  us,  that  relations  which  are 
probable  in  the  environment  are  probable  in  us,  that  re- 
lations which  are  fortuitous  in  the  environment  are  for- 
tuitous in  UB. 


CHAPTEE  m. 

THE  GEOWTH  OF  INTELLIGENCE. 

§  188.  The  law  enunciated  in  the  foregoing  chapter, 
being  the  law  of  Intelligence  in  the  abstract — the  law  which 
Intelligence  fulfils  more  and  more  the  further  it  advances, 
we  have  next  to  examine  the  modes  in  which  better  fulfil- 
ment of  the  law  is  exhibited ;  and  to  seek  the  general  cause 
for  this  ever-increasing  fulfilment  of  it. 

Three  ways  in  which  progress  shows  itself  may  be  dis- 
tinguished. There  is,  first — increase  in  the  accuracy  with 
which  the  inner  tendencies  are  proportioned  to  the  outer 
persistences.  There  is,  second — increase  in  the  number  of 
cases,  unlike  as  to  kind  but  like  as  to  grade  of  complexity, 
in  which  there  are  inner  tendencies  answering  to  outer  per- 
sistences. And  there  is,  third — increase  in  the  complexity 
of  the  coherent  states  of  consciousness,  answering  to  coherent 
complexities  in  the  environment.  The  organism  is  placed 
amid  innumerable  relations  of  all  orders.  It  begins  by 
imperfectly  adjusting  its  actions  to  a  few  of  the  simplest  of 
these.  To  adjust  its  actions  more  exactly  to  these  few  sim- 
plest, is  one  form  of  advance.  To  adjust  its  actions  to  a 
greater  variety  of  these  simplest,  is  a  further  form  of  ad- 
vance. To  a:djust  its  actions  to  successive  grades  of  the  more 
complicated,  is  yet  another  form  of  advance.  And  to  what- 
ever stage  it  reaches  there  are  still  the  same  three  kinds  of 
improvement  open  to  it — a  perfecting  of  the  correspond- 
ences already  achieved;  an  achievement  of  other  corre- 

418 


THE   GROWTH  OF  INTELLIGEiNCE.  419 

spondences  of  the  same  order;  and  an  achievement  of  cor- 
respondences of  a  higher  order :  all  of  them  implying  greater 
fulfilment  of  the  law  of  intelligence. 

But  now,  what  are  the  requisites  to  this  progress?  Is  the 
genesis  of  Intelligence  explicable  on  any  one  general  prin- 
ciple applying  at  once  to  all  these  modes  of  advance?  If  so, 
what  is  this  general  principle? 

§  189.  In  the  environment  there  exist  relations  of  all 
orders  of  persistence,  from  the  absolute  to  the  fortuitous. 
Consequently,  in  a  creature  displaying  a  developed  corre- 
spondence, there  must  exist  all  grades  of  strength  in  the 
connexions  between  states  of  consciousness.  As  a  high 
intelligence  is  only  thus  possible,  it  is  manifestly  a  condition 
to  intelligence  in  general  that  the  antecedents  and  con- 
sequents of  psychical  changes  shall  admit  of  all  degrees  of 
cohesion.  And  the  question  to  be  answered  is: — How  are 
their  various  degrees  of  cohesion  adjusted? 

Concerning  their  adjustments  there  are  two  possible  hy- 
potheses, of  which  all  other  hypotheses  can  be  but  modi- 
fications. On  the  one  hand,  it  may  be  asserted  that  the 
strength  of  the  tendency  which  each  state  of  consciousness 
has  to  follow  any  other,  is  fixed  beforehand  by  a  Creator — 
that  there  is  a  "  pre-established  harmony  "  between  the 
inner  and  outer  relations.  On  the  other  hand,  it  may  be 
asserted  that  the  strength  of  the  tendency  which  each  state 
of  consciousness  has  to  follow  any  other,  depends  on  the 
frequency  with  which  the  two  have  been  connected  in  ex- 
perience— that  the  harmony  between  the  inner  and  outer 
relations  arises  from  the  fact  that  the  outer  relations  produce 
the  inner  relations.  Let  us  briefly  examine  these  two 
hypotheses. 

For  the  first  the  reason  given,  like  the  reason  given  for 
the  special-creation  hypothesis  at  large,  is  that  certain  of 
the  phenomena  cannot  otherwise  be  explained.    This  super- 
natural genesis  of  the  adjustment  is  alleged  because  no 
28 


430  SPECIAL  SYNTHESIS. 

natural  genesis  has  been  assigned.  The  hypothesis  has  not 
a  single  fact  to  rest  on.  The  facts  that  may  be  cited  in  its 
support,  such  as  those  of  reflex  action,  are  simply  facts  which 
have  not  yet  been  explained;  and  this  alleged  explanation 
of  them  as  due  to  a  pre-established  harmony,  is  simply  a 
disguised  mode  of  shelving  them  as  inexplicable.  A 

further  criticism  is,  that  those  who  espouse  this  theory  dare 
not  apply  it  beyond  a  narrow  range  of  cases.  It  is  only 
where  the  connexions  between  psychical  states  are  absolute 
— as  in  the  so-called  forms  of  thought  and  in  the  congenital 
instincts — that  they  fall  back  on  "pre-established  harmony." 
But  they  should  either  go  the  entire  length  with  Leibnitz, 
or  not  go  with  him  at  all.  If  they  assume  that  the  adjust- 
ment of  inner  relations  to  outer  relations  has  been  in  some 
cases  fixed  beforehand,  they  ought  in  consistency  to  assume 
that  it  has  been  in  all  cases  fixed  beforehand.  If,  answering 
to  each  absolutely-persistent  connexion  of  phenomena  in  the 
environment,  there  has  been  provided  some  absolutely-per- 
sistent connexion  between  states  of  consciousness;  why, 
where  the  outer  connexion  is  almost  absolutely  persistent, 
and  the  inner  connexion  proportionately  persistent,  must  we 
not  suppose  a  special  provision  here  also?  why  must  we  not 
suppose  special  provisions  for  all  the  infinitely- varied  degrees 
of  persistence?  The  unqualified  adoption  of  the 

hypothesis  is,  however,  declined,  for  obvious  reasons.  It 
would  involve  the  assertion  of  a  rigorous  necessity  in  all 
thought  and  action — an  assertion  which  those  who  favour 
this  hypothesis  are,  more  than  any  others,  disinclined  to 
make.  It  would  raise  the  awkward  question  why  at  birth 
there  is  not  as  great  a  power  of  thinking,  and  of  thinking 
correctly,  as  at  any  subsequent  period.  It  would  imply  that 
men  are  equally  wise  concerning  things  of  which  they  have 
had  no  experience,  as  concerning  things  of  which  they  have 
had  experience.  It  would  altogether  negative  that  advance 
in  enlightenment  which  characterizes  human  progression. 
In  short,  not  only  is  the  hypothesis  without  foundation 


THE  GROWTH  OF  INTELLIGENCE.  421 

in  our  knowledge  of  mental  phenomena;  but  acceptance 
of  it  would  necessitate  rejection  of  all  such  knowledge  of 
mental  phenomena  as  we  have  acquired. 

Contrariwise,  for  the  second  hypothesis  the  evidence  is 
overwhelming.  The  multitudinous  facts  commonly  cited  to 
illustrate  the  doctrine  of  association  of  ideas,  support  it. 
It  is  in  harmony  with  the  general  truth  that  from  the  igno- 
rance of  the  infant  the  ascent  is  by  slow  steps  to  the  know- 
ledge of  the  adult.  All  theories  and  all  methods  of  educa- 
tion take  it  for  granted — are  alike  based  on  the  belief  that 
the  more  frequently  states  of  consciousness  are  made  to 
follow  one  another  in  a  certain  order,  the  stronger  becomes 
their  tendency  to  suggest  one  another  in  that  order.  The 
sayings — "  Practice  makes  perfect,"  and  "  Habit  is  second 
nature,"  remind  us  how  long-established  and  universal  is 
the  conviction  that  such  a  law  exists.  Exemplification  of 
it  is  furnished  by  the  fact  that  men  who,  from  being  diffe- 
rently circumstanced,  have  had  different  experiences,  reach 
different  generalizations;  and  by  the  fact  that  a  wrong 
conception  will  become  as  firmly  established  as  a  right  one, 
if  the  external  relation  to  which  it  answers  has  been  as 
often  repeated.  It  is  in  harmony  with  these  among  other 
familiar  truths; — that  phenomena  wholly  unrelated  in  our 
experience,  we  have  no  tendency  to  think  of  together ;  that 
where  a  certain  phenomenon  has  occurred  in  many  rela- 
tions, we  usually  imagine  it  as  recurring  in  the  relation  in 
which  it  has  most  frequently  occurred ;  that  when  we  have 
witnessed  many  recurrences  of  a  certain  relation  we  come 
to  have  a  strong  belief  in  that  relation;  that  if  a  relation 
has  been  daily  experienced  throughout  life  with  scarcely  ^n 
exception,  it  becomes  difficult  for  us  to  conceive  it  as  other- 
wise— to  break  the  connexion  between  the  states  of  con- 
sciousness representing  it;  and  that  where  a  relation  has 
been  perpetually  repeated  in  our  experience  with  absolute 
uniformity,  we  are  entirely  disabled  from  conceiving  the 
negation  of  it. 


423  SPECIAL  SYNTHESIS. 

The  only  orders  of  psychical  sequences  not  obviously  in- 
cluded by  this  general  law,  are  those  classed  as  reflex  and 
instinctive — those  which  are  apparently  established  before 
any  experience  has  been  had.  But  it  is  possible  that,  rightly 
interpreted,  the  law  covers  these  also.  Though  reflex  and 
instinctive  sequences  are  not  determined  by  the  experiences 
of  the  individnal  organism  manifesting  them;  yet  the  ex- 
periences of  the  race  of  organisms  forming  its  ancestry  may 
have  determined  them.  Hereditary  transmission  applies  to 
psychical  peculiarities  as  well  as  to  physical  peculiarities. 
While  the  modified  bodily  structure  produced  by  new 
habits  of  life  is  bequeathed  to  future  generations,  the 
modified  nervous  tendencies  produced  by  such  new  habits 
of  life  are  also  bequeathed;  and  if  the  new  habits  of  life 
become  permanent  the  tendencies  become  permanent.  Let 
us  glance  at  the  facts. 

Among  the  families  of  a  civilized  society,  the  changes  of 
occupation  and  habit  from  generation  to  generation  and  the 
intermarriage  of  families  having  different  occupations  and 
habits,  greatly  confuse  the  evidence  of  psychical  here- 
dity. But  it  needs  only  to  contrast  national  characters 
to  see  that  mental  peculiarities  caused  by  habit  become  here- 
ditary. We  know  that  there  are  warlike,  peaceful,  nomadic, 
maritime,  hunting,  commercial,  races — races  that  are  inde- 
pendent or  slavish,  active  or  slothful;  we  know  that  many 
of  these,  if  not  all,  have  a  common  origin;  and  hence  it  is 
inferable  that  these  varieties  of  disposition,  which  have 
evident  relations  to  modes  of  life,  have  been  gradually 
produced  in  the  course  of  generations.  The  tendencies  to 
certain  combinations  of  psychical  changes  have  become 
organic.  In  domesticated  animals  parallel  facts 

are  familiar.  Not  only  the  forms  and  constitutions,  but  the 
dispositions  and  instincts  of  horses,  oxen,  sheep,  pigs,  fowls, 
have  become  different  from  those  of  their  wild  kindred. 
The  various  breeds  of  dogs  exhibit  numerous  varieties 
of  mental  character  and  faculty  permanently  established 


THE  GROWTH  OF  INTELLIGENCE.  423 

by  mode  of  life;  and  their  several  tendencies  are  spontane- 
ously manifested.  A  young  pointer  will  point  at  a  covey 
the  first  time  he  is  taken  afield.  A  retriever  brought  up 
abroad  has  been  remarked  to  fulfil  his  duty  without  instruc- 
tion. In  such  cases  there  is  evidently  a  bequeathed  ten- 
dency for  the  psychical  changes  to  take  place  in  a  special 
way.*  Even  from  the  conduct  of  untamed  creatures 

we  may  gather  evidence  having  like  implications.  The 
birds  of  inhabited  countries  are  far  more  difficult  to  ap- 
proach than  those  of  uninhabited  ones.  And  the  manifest 
inference  is,  that  continued  experience  of  human  enmity 
has  wrought  organic  changes  in  them — has  modified  their 
instincts — has  altered  the  connexions  among  their  psychical 
states,  f 

Of  the  two  hypotheses,  then,  the  first  is  supported  by  no 
positive  evidence  whatever,  while  the  second  is  supported 
by  such  positive  evidence  as  we  have.     That  the  inner  co- 

*  Had  Mr.  Darwin's  Origin  of  Species,  been  published  before  I  wrote 
this  paragraph,  I  should,  no  doubt,  have  so  qualified  my  words  as  to  re- 
cognize "  selection,"  natural  or  artificial,  as  a  factor.  Being  written,  how- 
ever, I  prefer  to  let  the  passage  remain  with  nothing  beyond  verbal 
changes,  and  to  make  the  needful  qualification  in  a  note.  I  do  this  partly 
to  avoid  an  inconvenient  complication  of  the  statement.  But  my  chief 
reason  is  that,  while  holding  survival  of  the  fittest  to  be  always  a  co- 
operating cause,  I  believe  that  in  cases  like  these  it  is  not  the  chief  cause. 
The  reasons  for  this  belief  are  given  in  the  Principles  of  Biology,  §  166. 

f  I  was  somewhat  surprised  when  a  very  competent  critic  called  in  ques- 
tion this  modification  of  instincts  in  birds ;  and  failing  to  remember  on 
what  authority  I  had  alleged  the  fact  (which  I  supposed  to  be  well  known) 
I  was  unable  to  justify  myself.  An  American  friend,  who  was  present, 
has  since  been  so  good  as  to  forward  me  a  verification,  in  the  form  of  an 
incidental  remark  contained  in  a  letter  from  Captain  William  Reynolds, 
of  the  United  States  Navy.  This  letter  (the  original  is  before  me)  is 
written  from  Brook's  Island,  described  by  Captain  Reynolds  as  a  "  little 
midge  of  sand  in  the  midst  of  the  wide  Pacific."  After  giving  other 
particulars  of  this  uninhabited  island,  he  says : — "  The  birds  won't  get 
out  of  the  way  of  our  people  when  we  land,  but  show  fight  and  have  to 
be  kept  off  with  sticks.  During  this  melie,  the  tropic  birds  lose  their  tail 
feathers,  which  are  plucked  from  them,  as  you  would  pull  a  blade  of 
grass,  while  walking  over  a  field." 


424  SPECIAL  SYNTHESIS. 

hesions  of  psychical  states  are  pre-adjusted  to  the  outer 
persistences  of  the  relations  symbolized,  is  a  supposition 
which,  if  taken  literally,  involves  absurdities  so  great  that 
none  now  make  it  in  respect  of  any  cohesions  save  the  con- 
genital. That  it  is  the  true  supposition  in  so  far  as  this 
limited  range  of  cases  is  concerned,  no  evidence  can  be 
given;  since  only  to  one  present  at  the  creation  of  an 
organism  is  knowledge  of  pre-adjustment  possible.  So  far 
as  the  facts  are  accessible,  the  supposition  is  wholly  at 
variance  with  them;  and  it  is  entertained  only  where  it 
cannot  be  brought  face  to  face  with  the  facts.  On 

the  other  hand,  the  supposition  that  the  inner  cohesions  are 
adjusted  to  the  outer  persistences  by  accumulated  ex- 
perience of  those  outer  persistences,  is  in  harmony  with  all 
our  actual  knowledge  of  mental  phenomena.  Though  in 
so  far  as  reflex  actions  and  instincts  are  concerned,  the 
experience-hypothesis  seems  insufficient;  yet,  its  seeming 
insufficiency  occurs  only  where  the  evidence  is  beyond  our 
reach.  Nay,  even  here,  such  few  facts  as  we  can  get  point 
to  the  conclusion  that  automatic  psychical  connexions  result 
from  the  registration  of  experiences  continued  for  number- 
less generations. 

In  brief,  the  case  stands  thus: — It  is  agreed  that  all  psychi- 
cal relations  save  the  absolutely  indissoluble  are  determined 
by  experiences.  Their  various  strengths  are  admitted,  other 
things  equal,  to  be  proportionate  to  the  multiplication  of  ex- 
periences. It  is  an  unavoidable  corollary  that  an  infinity  of 
experiences  will  produce  a  psychical  relation  that  is  in- 
dissoluble. Though  such  infinity  of  experiences  cannot  be 
received  by  a  single  individual,  yet  it  may  be  received  by 
the  succession  of  individuals  forming  a  race.  And  if  there  is 
a  transmission  of  induced  tendencies  in  the  nervous  system, 
it  is  inferable  that  all  psychical  relations  whatever,  from  the 
necessary  to  the  fortuitous,  result  from  the  experiences  of 
the  corresponding  external  relations;  and  are  so  brought 
into  harmony  with  them. 


THE  GROWTH  OP  INTELLIGENCE.  425 

Hence  the  growth  of  intelligence  at  large  depends  on  the 
law,  that  when  any  two  psychical  states  occur  in  immediate 
succession,  an  effect  is  produced  such  that  if  the  first  sub- 
sequently recurs  there  is  a  certain  tendency  for  the  second 
to  follow  it. 

§  190.  By  this  law,  if  it  is  the  true  one,  must  be  interpret- 
able  all  the  phenomena,  from  their  lowest  to  their  highest 
grades.  Let  us  first  observe  how  far  the  leading  deductions 
agree  with  the  leading  facts. 

A  manifest  corollary  from  the  law  is  that  the  psychical 
relations  in  any  organism,  will  correspond  best  to  those 
physical  relations  it  comes  most  in  contact  with.  The 
environment  in  general  is  infinite.  The  environment  of 
each  order  of  creature  is  practically  more  or  less  limited. 
And  each  order  of  creature  has  an  environment  which, 
besides  being  limited,  is  practically  more  or  less  special. 
The  law  implies,  then,  that  the  psychical  relations  displayed 
by  each  order  of  creature,  will  be  those  which  recur  the 
oftenest  within  the  range  of  its  experience.  And  we  know 
the  fact  to  be  that  they  are  so. 

Contemplating  the  animal  kingdom  at  large,  the  first  psy- 
chical relations  established  ought  to  be  those  answering  to 
the  most  prevalent  environing  relations  of  the  simplest  kind. 
Such  are  just  what  we  find.  The  stationary  polype  with  out- 
stretched tentacles,  contracts  on  being  touched.  ISTow  a 
creature  that  is  not  itself  moving  can  be  touched  only  by 
something  in  motion.  And  this  universal  relation  between 
collision  and  some  moving  body,  is  one  of  the  first  to  be  re- 
sponded to.  When  a  shadow  passing  across  a  rudimentary 
eye  is  followed  by  a  movement  in  the  creature  possessing 
that  eye,  the  internal  relation  between  the  impression  and 
the  motion  corresponds  with  the  relation  between  a  passing 
opacity  and  a  passing  solidity  in  the  environment ;  and  this 
is  one  of  the  most  general  relations.  Various  analogous 
cases  will  suggest  themselves. 


436  SPECIAL  SYNTHESI& 

In  the  progress  of  life  at  large,  as  in  the  progress  of  the 
individual,  the  adjustment  of  inner  tendencies  to  outer  per- 
sistences, must  begin  with  the  simple  and  advance  to  the 
complex;  seeing  that  both  within  and  without,  complex  re- 
lations, being  made  up  of  simple  ones,  cannot  be  established 
before  simple  ones  have  been  established.  After  experience 
of  some  persistent  relation  A  to  B  in  the  environment  has 
generated  a  persistent  relation  between  the  answering  psy- 
chical states  a  and  &;  and  after  some  other  persistent  outer 
relation  C  to  D,  has  similarly  generated  a  persistent  inner 
relation  ctod'^  then,  if  in  the  environment  there  exists  any 
relation  between  the  relations  A  to  B  and  C  to  D,  it  becomes 
possible  for  repeated  experiences  to  generate  in  the  organism 
a  relation  between  a  to  6  and  c  to  d.  But  it  is  manifestly 
impossible  for  this  to  be  done  until  the  relations  a  to  6  and 
cto  d  have  been  themselves  generated.  This  deduction,  too, 
we  see  to  be  in  complete  conformity  with  the  facts,  both  of 
individual  evolution  and  of  general  evolution. 

Further,  it  must  follow  that  the  only  thing  required  for 
the  establishment  of  a  new  internal  relation  answering  to  a 
new  external  one,  is,  that  the  organism  shall  be  sufficiently 
developed  to  cognize  the  two  terms  of  the  new  relation,  and 
that  being  thus  developed,  it  shall  be  placed  in  circumstances 
which  present  the  new  relation.  Here  also,  there  is  har- 
mony between  the  dj[}riorimieTence  and  the  inference  from 
observation.  In  our  domestic  animals  there  are  constantly 
formed  new  psychical  relations  answering  to  such  new  phy- 
sical relations  as  have  terms  sufficiently  simple  to  be  per- 
ceived. And  in  human  civilization  we  see  the  truth 
illustrated  in  the  progress  to  wider  and  wider  general- 
izations. 

But  the  validity  of  these  several  corollaries  will  become 
more  apparent  as  we  proceed.  Let  us  now  pass  on  to  con- 
template the  growth  of  Intelligence  under  its  leading 
aspects. 


CHAPTER  IV. 


REFLEX    ACTION. 


§  191.  Under  its  simplest  form,  Reflex  Action  is  the 
sequence  of  a  single  contraction  upon  a  single  irritation. 
A  vague  manifestation  of  this  sequence  marks  the  dawn  of 
sensitive  life;  and,  indeed,  it  is  chiefly  because  they  shrink 
on  being  touched,  that  many  of  the  simpler  animals  are 
recognized  as  living. 

But  though  in  the  movements  of  Zoophytes  it  is  fore- 
shadowed, Reflex  action  proper  is  exhibited  only  when 
we  ascend  to  creatures  in  which  there  exist  nerves 
and  muscles.  In  such  creatures,  the  response  is  effected 
not  through  the  agency  of  the  one  uniform  tissue  consti- 
tuting the  body,  which  is  at  once  irritable  and  contractile; 
but  the  irritability  is  confined  to  one  specialized  struc- 
ture, while  the  contractility  is  confined  to  another  special- 
ized structure;  and  the  two  structures  are  placed  in  such 
relation  that  irritation  of  the  one  is  followed  by  contraction 
of  the  other.  Some  impression  is  made  on  the  peripheral 
termination  of  a  nerve;  the  molecular  motion  it  sets  up  is 
propagated  along  the  nerve  until  it  reaches  a  ganglion ;  the 
large  quantity  of  molecular  motion  there  disengaged,  dis- 
charges itself  along  another  nerve  proceeding  from  the 
ganglion  to  a  muscle;  and  thus  the  stimulus  carried 
through  an  afferent  nerve  to  some  lib&fo-motor  centre,  is 
thence  reflected  in  multiplied  amount  through  an  efferent 

nerve  to  the  contractile  agent. 

427 


428  SPECIAL  SYNTHESIS. 

In  this  simplest  form  of  psychical  action  we  see  a  single 
internal  relation  adjusted  to  a  single  external  relation. 
Any  one  of  the  suckers  on  the  arm  of  a  cuttle-fish  that  has 
been  separated  from  the  body,  will,  under  the  influence  of 
its  own  independent  ganglion,  attach  itself  to  a  substance 
placed  in  contact  with  it — the  established  relation  between 
the  tactual  and  muscular  changes  in  the  sucker  and  its 
ganglion,  is  parallel  to  the  uniform  relation  between  resist- 
ance and  extension  in  its  environment — the  inner  cohesion 
of  psychical  states  is  as  persistent  as  is  the  outer  relation 
between  attributes.  And  if  we  remember  that  in  the 
actions  of  the  cuttle-fish  this  inner  relation  is  perpetually 
being  repeated  in  response  to  the  outer  relation,  we  see  how 
the  organization  of  it  in  the  species  answers  to  the  infinitude 
of  experiences  received  by  the  species. 

§  192.  Reflex  action  being  the  lowest  form  of  psychical 
life,  is,  by  implication,  most  nearly  related  to  physical  life: 
in  it  we  see  the  incipient  differentiation  of  the  two.  This 
truth  may  be  discerned  from  several  points  of  view. 

It  was  shown  that  the  contraction  which  occurs  in  a 
polype  when  touched,  or  otherwise  stimulated,  probably 
results  from  the  increased  vital  change  which  the  stimulus 
produces  in  the  disturbed  tissues  (§  140) ;  and  though  one  of 
these  reflex  actions,  as  of  a  cephalopod's  sucker,  is  effected 
in  a  more  definite  and  more  complicated  way,  yet  it  does 
not  so  far  differ  as  to  be  removable  from  the  class  of  phy- 
sical actions.  Mostly,  it  would  be  considered  as  a  misuse  of 
words  to  call  it  psychical.  So  that  while  as  belonging  to  the 
order  of  vital  changes  which,  in  their  higher  complications, 
we  dignify  as  psychical,  it  may  be  convenient  to  classify  it 
as  psychical;  yet  it  must  be  admitted  that  in  position  it  is 
transitional.  Again,  in  well-organized  creatures, 

the  physical  life  is  itself  regulated  by  reflex  actions.  Those 
rhythmical  movements  of  the  alimentary  canal  which  follow 
the  introduction  of  food,  are  of  reflex  origin;  as  are  also 


REFLEX  ACTION.  429 

those  processes  by  which,  under  the  same  stimulus,  the 
digestive  fluids  are  prepared  and  poured  out.  The  various 
viscera,  too,  performing  each  its  separate  function,  must 
have  their  relative  activities  adjusted;  and  the  due  bal- 
ancing of  them  is  effected  by  reflex  action.  It  is  held  that 
the  changes  in  the  state  of  each  viscus  are  impressed  on  the 
nerves  proceeding  to  ganglia  in  the  sympathetic,  whence 
they  are  reflected  to  the  other  viscera;  so  that,  for  instance, 
when  the  stomach  has  been  filled,  the  stimulus  it  diffuses 
through  this  channel  to  the  heart  and  lungs,  causes  them  to 
send  it  an  increased  quantity  of  aerated  blood.  In 

yet  another  respect  may  we  see  a  close  alliance  between  the 
physical  life  and  this  nascent  psychical  life.  As  was  shown 
in  a  foregoing  chapter,  the  psychical  life  is  broadly  distin- 
guished from  the  physical  life  by  the  peculiarity  that  its 
changes,  instead  of  being  simultaneous  and  successive,  are 
successive  only;  but,  as  was  also  shown,  this  peculiarity 
makes  its  appearance  gradually,  and  becomes  marked  only 
when  the  psychical  life  becomes  high.  Now  the  reflex 
actions  in  which  the  nascent  psychical  life  is  seen,  are 
nearly  as  much  characterized  by  simultaneity  as  are  the 
purely  physical  actions.  A  great  number  of  these  simplest 
nervous  changes  go  on  quite  independently  in  the  same 
organism  at  the  same  moment.  Once  more,  the 

proximity  of  these  reflex  actions  to  the  physical  life  is  im- 
plied by  their  unconsciousness.  N^ot  only  in  co-ordinating 
the  visceral  processes,  but  also  in  co-ordinating  the  pro- 
cesses of  perception,  there  constantly  go  on  reflex  actions 
of  which  we  have  no  immediate  knowledge;  as  those  by 
which  the  focus  of  each  eye  is  adjusted  to  distances  and  the 
closure  of  the  iris  adapted  to  the  quantity  of  light.  Other 
reflex  actions  of  which  we  can  take  direct  cognizance — as 
that  of  breathing — can  go  on  without  our  thinking  of  them. 
And  others  which  are  commonly  accompanied  by  local  sen- 
sation— as  when  the  foot  is  withdrawn  from  something 
which  tickles  it — are  found  to  be  most  energetically  per- 


480  SPECIAL  SYNTHESIS. 

formed  when,  from  some  spinal  lesion,  local  sensation  has 
been  abolished.  Remembering  how  nearly  unconscious  our 
own  locomotive  actions  become  when  we  are  absorbed  in 
thought,  it  is  inferable  that  in  creatures  whose  reflex  loco- 
motive actions  are  congenitally  perfect,  they  are  quite  un- 
conscious. The  rapid  alternations  of  a  centipede's  leg  or  a 
fly's  wing,  are  probably  as  automatic  as  are  those  of  a 
steam-engine  piston;  and  may  be  co-ordinated  after  a  gene- 
rally analogous  manner.  Just  as,  in  a  steam-engine,  the 
arrival  of  the  piston  at  a  certain  point  is  necessarily  accom- 
panied by  the  opening  of  a  valve  serving  to  admit  the  steam 
which  will  drive  the  piston  in  the  reverse  direction;  so,  in 
one  of  these  rhythmically-moving  organs,  the  performance 
of  each  motion  ends  in  bringing  the  organ  to  a  position  in 
which  the  stimulus  to  an  opposite  motion  acts  upon  it. 

But  though,  from  all  points  of  view,  Reflex  action  is  seen 
to  be  a  species  of  change  very  little  removed  from  the 
physical  changes  constituting  vegetative  life;  yet  even  in 
it  we  may  discern  a  fulfilment  of  the  primordial  conditions 
to  consciousness.  In  the  lowest  conceivable  type  of  con- 
sciousness— that  produced  by  the  alternation  of  two  states 
— there  are  involved  the  relations  constituting  the  forms  of 
all  thought.  And  such  an  alternation  of  two  states  is  just 
that  which  occurs  in  the  ganglion  connected  with  one  of 
these  rhythmically-moving  organs. 

§  193.  From  that  lowest  kind  of  Reflex  action  in  which  a 
single  impression  produces  a  single  contraction,  the  ascent 
is  to  complications  in  the  stimuli  and  in  the  acts  resulting 
from  them.  There  is  no  precise  distinction  between  a  single 
contraction  and  a  combination  of  contractions.  From  tlie 
excitation  of  dispersed  muscular  fibres  to  the  excitation  of 
fibres  aggregated  into  definite  bundles,  the  transition  is 
insensible;  and  there  is  similarly  a  gradual  passage  from 
single  contractions  to  combinations  of  contractions.  Hence, 
Tinder  the  head  of  Reflex  action  there  are  classed  numerous 


REFLEX  ACTION.  431 

cases  in  which  a  whole  group  of  muscular  motions  results 
from  one  impression.  The  decapitated  frog  which  leaps 
when  one  of  its  feet  is  irritated,  supplies  an  illustration.  To 
examine  the  varieties  and  complexities  of  Reflex  action,  is 
the  task  of  the  physiologist  rather  than  of  the  psychologist. 
Here  it  concerns  us  merely  to  note  the  bearing  of  the  phe- 
nomena on  the  general  argument. 

We  have  to  observe  that  these  simplest  of  psychical 
changes  correspond  to  external  relations  which  are  only 
one  degree  more  specialized  than  the  relations  to  which 
physical  changes  correspond.  While  the  processes  of  the 
purely  vegetative  life  are  in  adjustment  with  those  most 
general  relations  between  nutriment,  oxygen,  temperature, 
moisture,  light,  which  pervade  the  environment  at  large; 
these  lowest  processes  of  the  animal  life  are  in  adjustment 
with  the  most  general  relations  of  the  solid  bodies  con- 
tained in  the  environment:  as  those  between  tangibility 
and  solidity,  motion  and  life. 

Further,  it  is  to  be  noticed  that  in  conformity  with  the 
general  law  of  intelligence,  we  have,  in  one  of  these  reflex 
actions,  an  established  connexion  between  two  psychical 
states  answering  to  an  established  connexion  between  two 
external  phenomena.  'Not  that  the  inner  tendency  is 
exactly  proportionate  to  the  outer  persistency.  In  many 
cases  it  is  absolute  in  the  organism  though  by  no  means 
absolute  in  the  environment.  And  this  is  just  what  is  to 
be  looked  for  among  these  manifestations  of  nascent  in- 
telligence; since  the  adjustment  of  the  inner  tendencies  to 
the  outer  persistencies,  being  the  law  of  intelligence  in  the 
abstract,  cannot  be  fulfilled  where  the  intelligence  is  in- 
cipient. 

Lastly  may  be  named  the  fact,  that  these  indissolubly- 
connected  psychical  states  exist  where  there  are  perpetually- 
repeated  experiences  of  the  external  relations  to  which  they 
answer. 


CHAPTER  V. 


INSTINCT. 


§  194.  Not  using  the  word  as  the  vulgar  do,  to  designate 
all  other  kinds  of  intelligence  than  the  human,  but  restrict- 
ing it  to  its  proper  signification,  Instinct  may  be  described 
as — compound  reflex  action.  I  say  described  rather  than 
defined,  since  no  clear  line  of  demarkation  can  be  drawn 
between  it  and  simple  reflex  action.  As  remarked  in  the 
last  section,  the  dirigo-motor  processes  which  reflex  actions 
show  us,  pass  by  degrees  from  the  simple  to  the  complex; 
and  a  cursory  inspection  of  the  facts  shows  us  that  the 
recipio-motor  processes  do  the  like.  Nevertheless  we  may 
conveniently  distinguish,  as.  a  higher  order  of  these  auto- 
matic nervous  adjustments,  those  in  which  complex  stimuli 
produce  complex  movements. 

That  the  propriety  of  thus  marking  off  Instinct  from 
primitive  reflex  action  may  be  clearly  seen,  let  us  take 
examples.  "  A  fly-catcher,"  says  Dr.  Carpenter,  "  immedi- 
ately after  its  exit  from  the  egg,  has  been  known  to  peck  at 
and  capture  an  insect — an  action  which  requires  a  very 
exact  appreciation  of  distance,  as  well  as  a  power  of  pre- 
cisely regulating  the  muscular  movements  in  accordance 
with  it."  Now  this  action,  which  is  proved  by  the  circum- 
stances to  be  purely  automatic,  implies  the  combination  of 
many  stimuli.  The  excitation  of  certain  retinal  nerve-fibres 
must  be  one — an  excitation  which  is  itself  a  somewhat  spe- 


INSTINCT.  433 

cial  combination  of  excitations.  Another  component  in  the 
general  stimulus  must  be  that  proceeding  from  the  muscles 
by  which  the  eyes  are  directed.  And  yet  another  component 
must  be  that  proceeding  from  the  muscles  which  alter  the 
focal  adjustments  of  the  eyes.  Without  impressions  pro- 
ceeding from  both  these  sets  of  muscles,  it  would  be  im- 
possible for  the  head  to  be  guided  in  the  right  direction,  or 
for  the  beak  to  be  closed  at  the  right  moment.  Thus  the 
action  implies  impressions  on  retinal  nerves,  impressions 
on  nerves  proceeding  from  muscles  which  move  the  eyes, 
and  impressions  on  nerves  proceeding  from  muscles  which 
adjust  their  lenses — implies  that  all  these  nerves  are  excited 
simultaneously  in  special  ways  and  degrees;  and  that  the 
complex  co-ordination  of  muscular  contractions  by  which 
the  fly  is  caught,  is  the  result  of  this  complex  co-ordination 
of  stimuli.  Of  such  co-ordinated  acts  automati- 

cally resulting  from  co-ordinated  stimuli,  we  have  many 
illustrations  in  ourselves.  Though  originating  in  volition, 
our  ordinary  movements  are  performed  in  a  mode  just  like 
that  described.  When  putting  out  the  hand  to  grasp  an 
object  before  us,  we  are  unconscious  of  the  particular 
muscular  adjustments  made.  We  see  the  object,  and  in 
response  to  the  wish  for  it  the  arm  is  moved  in  a  fit 
way.  But  were  any  of  the  various  nervous  stimuli  in- 
volved in  the  perception  absent,  the  arm  would  not  be 
guided  aright.  That  is  to  say,  the  special  muscular  co-or- 
dination is  due  to  the  special  co-ordination  of  sensations 
received  from  the  eye  and  its  adjuncts:  volition  being  con- 
cerned merely  in  setting  the  process  going.  One  of  these 
actions  of  our  own  differs  from  that  of  the  newly-hatched 
fly-catcher  mainly  in  this,  that  whereas,  in  ourselves,  the 
impressions  and  motions,  being  almost  infinitely  varied  and 
severally  repeated  with  comparative  infrequency,  are  not 
congenitally  co-ordinated  but  are  co-ordinated  in  the  course 
of  our  first  years;  in  the  fly-catcher,  descended  from  a  race 
in  which  a  special  combination  is  perpetually  repeated  by 


434  SPECIAL  SYNTHESIS. 

every  individual  throughout  life,  this  combination  is  ready- 
organized. 

So  that  while  in  the  primitive  forms  of  reflex  action  a 
single  impression  is  followed  by  a  single  contraction ;  while 
in  the  more  developed  forms  of  reflex  action  a  single  im- 
pression is  followed  by  a  combination  of  contractions;  in 
this  which  we  distinguished  as  Instinct,  a  combination  of  im- 
pressions is  followed  by  a  combination  of  contractions ;  and 
the  higher  the  Instinct  the  more  complex  are  both  the 
directive  and  executive  co-ordinations.  Carrying  with  us 
this  conception,  let  us  now  contemplate  the  facts  in  con- 
nexion with  the  general  laws  we  are  tracing  out. 

§  195.  Instinct  is  obviously  further  removed  from  purely 
physical  life  than  is  simple  reflex  action.  While  simple 
reflex  action  is  common  to  the  internal  visceral  processes 
and  to  the  processes  of  external  adjustment,  Instinct  is  not. 
There  are  no  instincts  displayed  by  the  kidneys,  the  lungs, 
the  liver:  they  occur  only  among  the  actions  of  that  nervo- 
muscular  apparatus  which  is  the  agent  of  psychical  life. 

Again,  the  co-ordination  of  many  stimuli  into  one  sti- 
mulus is,  so  far  as  it  goes,  a  reduction  of  diffused  simul- 
taneous changes  into  concentrated  serial  changes.  Whether 
the  combined  nervous  acts  which  take  place  when  the  fly- 
catcher seizes  an  insect,  are  regarded  as  a  series  passing 
through  its  centre  of  co-ordination  in  rapid  succession,  or  as 
consolidated  into  two  successive  states  of  its  centre  of  co- 
ordination, it  is  equally  clear  that  the  changes  going  on  in 
its  centre  of  co-ordination  have  a  much  more  decided  linear 
arrangement  than  have  the  changes  going  on  in  the  scat- 
tered ganglia  of  a  centipede. 

In  its  higher  forms.  Instinct  is  probably  accompanied  by 
a  rudimentary  consciousness.  There  cannot  be  co-ordination 
of  many  stimuli  without  some  ganglion  through  which  they 
are  all  brought  into  relation.  In  the  process  of  bringing 
them  into  relation,  this  ganglion  must  be  subject  to  the 


INSTINCT.  435 

influence  of  each — must  undergo  many  changes.  And  the 
quick  succession  of  changes  in  a  ganglion,  implying  as  it 
does  perpetual  experiences  of  differences  and  likenesses, 
constitutes  the  raw  material  of  consciousness.  The  implica- 
tion is  that  as  fast  as  Instinct  is  developed,  some  kind  of 
consciousness  becomes  nascent. 

Further,  the  instinctive  actions  are  more  removed  from 
the  actions  of  simple  bodily  life  in  this,  that  they  answer  to 
external  phenomena  which  are  more  complex  and  more 
special.  While  the  purely  physical  processes  going  on 
throughout  the  organism  respond  to  those  most  general 
relations  common  to  the  environment  as  a  whole ;  while  the 
simple  reflex  actions  respond  to  some  of  the  general  relations 
common  to  the  individual  objects  it  contains;  these  com- 
pound reflex  actions  which  we  class  as  instincts,  respond  to 
those  more  involved  relations  which  characterize  certain 
orders  of  objects  and  actions  as  distinguished  from  others. 

Greater  differentiation  of  the  psychical  life  from  the  phy- 
sical life  is  thus  shown  in  several  ways — in  the  growing 
distinction  between  the  action  of  the  vegetative  and  animal 
systems;  in  the  increasing  seriality  of  the  changes  in  the 
animal  system;  in  the  consequent  rise  of  incipient  con- 
sciousness; and  in  the  higher  speciality  of  the  outer  relations 
to  which  inner  relations  are  adjusted:  which  last  is  indeed 
the  essence  of  the  advance,  to  which  the  others  are  necessary 
accompaniments. 

§  196.  We  are  now  prepared  to  inquire  how,  by  ac- 
cumulated experiences,  compound  reflex  actions  may  be 
developed  out  of  simple  ones. 

Let  us  begin  with  some  low  aquatic  creature  possessing 
rudimentary  eyes.  Sensitive  as  such  eyes  are  only  to 
marked  changes  in  the  quantity  of  light,  they  cati  be  affected 
by  opaque  bodies  moving  in  the  surrounding  water,  only 
when  such  bodies  approach  close  to  them.  But  bodies 
carried  by  their  motion  very  near  to  the  organism,  will,  by 
29 


436  SPECIAL  SYNTHESIS. 

their  further  motion,  be  brought  in  contact  with  it.  The 
cases  in  which  an  external  object  passes  by  almost  at  a  tan- 
gent to  that  part  of  the  organism  where  the  rudimentary  eye 
is  placed,  so  as  nearly  to  touch  the  surface  but  not  quite, 
must  be  exceptional.  In  its  earliest  forms  sight  is,  as  before 
said,  little  more  than  anticipatory  touch  (§  142):  visual 
impressions  are  habitually  followed  by  tactual  ones.  But 
tactual  impressions  are,  in  all  these  creatures,  habitually 
followed  by  contractions — contractions  which,  as  was 
pointed  out  in  §  140,  are  probably  the  necessary  effects  of 
mechanically  accelerating  the  vital  changes — contractions 
which,  under  like  stimuli,  occur  even  in  certain  plants,  and 
are  so  shown  to  be  producible  by  alterations  in  the  processes 
of  purely  physical  life.  Result  as  they  may,  however,  it  is 
beyond  question  that  from  the  zoophytes  upwards,  touch 
and  contraction  form  an  habitual  sequence;  and  hence,  in 
creatures  whose  incipient  vision  amounts  to  little  more  than 
anticipatory  touch,  there  constantly  occurs  the  succession 
— a  visual  impression,  a  tactual  impression,  a  contrac- 
tion. Now  the  evolution  of  a  nervous  system  is  a 
necessary  concomitant  of  that  specialization  which  originates 
the  senses.  On  the  one  hand,  until  the  general  sensitiveness 
is  in  some  degree  localized,  the  intemuncial  function  of  the 
nervous  system  cannot  exist;  and  on  the  other  hand,  no  such 
localized  sensitiveness  can  exist  without  something  in  the 
shape  of  nerves.  A  nascent  sense  of  sight,  therefore,  implies 
a  nascent  nervous  communication.  And  along  with  a  nas- 
cent nervous  communication  we  may  see  the  first  illustration 
of  the  growth  of  intelligence.  If  psychical  states  (using 
the  term  in  its  widest  sense)  which  follow  one  another  time 
after  time  in  a  certain  order,  become  every  time  more  closely 
connected  in  this  order,  so  as  eventually  to  become  insepar- 
able ;  then  it  must  happen  that  if,  in  the  experience  of  any 
species,  a  visual  impression,  a  tactual  impression,  and  a  con- 
traction, are  continually  repeated  in  this  succession,  the 
several  nervous  states  produced  will  become  so  consolidated 


INSTINCT.  437 

ttat  the  first  cannot  be  caused  without  the  others  following 
— the  visual  impression  will  be  instantly  succeeded  by  a 
nervous  excitation  like  that  which  a  tactual  impression  pro- 
duces, and  this  will  be  instantly  succeeded  by  a  contraction. 
There  will  thus  occur  a  contraction  in  anticipation  of  touch. 

What  must  result  from  a  further  development  of  vision? 
Evidently  the  same  bodies  will  be  discerned  at  greater 
distances,  and  smaller  bodies  will  be  discerned  when  close 
to.  Both  of  these  must  produce  obscurations  which  are  faint 
in  comparison  with  that  obscuration  produced  by  a  large 
body  about  to  strike  the  creature's  surface.  But  now  mark 
the  accompanying  experience.  A  faint  obscuration  will 
not,  like  an  extreme  one,  be  habitually  followed  by  a 
strong  tactual  impression  and  a  subsequent  contraction.  If 
caused  by  a  great  mass  passing  at  some  distance,  there 
will  probably  be  no  collision — no  tactual  impression  at  all. 
If  caused  by  a  little  mass  which  is  very  near,  the  collision 
that  follows  will  be  comparatively  slight — so  slight  as  not  to 
excite  a  violent  contraction,  but  only  such  tension  in  the 
muscular  apparatus  as  is  seen  in  any  creature  about  to  seize 
upon  prey.  This  is  by  no  means  an  assumption.  Among 
animals  in  general,  ourselves  included,  a  nervous  impression 
which,  if  slight,  simply  rouses  attention  and  braces  up  the 
muscles,  causes  convulsive  contortions  if  intense.  It  is  there- 
fore a  deduction  from  a  well-established  law  of  the  nervo- 
muscular  system,  that  a  creature  possessing  this  somewhat 
improved  vision  will,  by  a  partial  obscuration  of  light,  have 
its  muscles  brought  into  a  state  of  partial  tension — a  state 
fitting  them  either  for  the  seizure  of  a  small  animal  should 
the  partial  obscuration  be  caused  by  the  impending  collision 
of  one,  or  for  sudden  retreat  into  a  shell  should  the  obscura- 
tion be  increased  by  the  near  approach  of  a  larger  animal. 
So  that  even  from  this  simple  advance  there  arises  a  some- 
what great  speciality  and  complexity  in  the  inner  relations 
answering  to  outer  relations. 

Instead  of  a  stationary  creature,  suppose  the  creature  con- 


488  SPECIAL  SYNTHESIS. 

templated  to  be  one  that  habitually  moves  about  in  the 
water;  and  suppose  a  further  development  of  the  eyes — a 
development  consisting  in  enlargement  of  each  retina,  and 
subdivision  of  it  into  separate  sensitive  agents.  In  such  a 
creature,  the  eyes  are  subject  to  perpetually-changing  im- 
pressions produced  by  the  objects  amid  which  it  swims. 
These  impressions  fall  on  different  parts  of  its  retinae, 
according  to  the  positions  of  the  objects  making  them. 
Laterally-placed  bodies  either  affect  one  retina  only,  or  one 
much  more  than  the  other.  Bodies  above  have  their  images 
cast  on  the  lower  parts  of  its  retinae.  Bodies  below,  if 
visible  at  all,  cast  images  on  their  upper  parts.  Of  the  im- 
pressions thus  made,  however,  few  are  directly  followed  by 
tactual  impressions:  the  creature's  forward  movement  car- 
ries it  away  from  the  objects  making  them.  Only  when  the 
impression  made  by  a  lateral  object  is  both  very  strong  and 
changes  very  rapidly — only  when  it  is  the  impression  pro- 
duced by  an  approaching  larger  animal,  will  there  result  any 
motor  excitation.  Faint  and  slowly-changing  lateral  impres- 
sions, not  being  habitually  followed  by  tactual  impressions, 
will  not  affect  the  actions.  But  now  mark  that  there 

are  certain  visual  impressions  which,  though  not  strong,  are 
habitually  followed  by  tactual  ones  of  a  particular  kind. 
I  refer  to  the  visual  impressions  made  by  small  objects  in 
front.  When,  during  the  creature's  passage  through  the 
water,  certain  parts  of  its  two  retinae  are  simultaneously 
affected  by  impressions  of  moderate  strength ;  it  commonly 
happens  that  immediately  afterwards,  the  feelers  and  head 
come  in  contact  with  something  serving  for  food.  A  visual 
impression  of  a  special  kind,  is  followed  by  a  tactual  im- 
pression on  the  prehensile  organs;  and,  consequently,  by  all 
those  muscular  actions  which  the  presentation  of  food  to 
them  calls  forth.  The  often-recurring  succession  will  be 
this: — Slight  excitation  of  a  particular  double  group  of  re- 
tinal nerves;  excitation  of  the  nerves  of  the  prehensile 
organs;  excitation  of  a  special  set  of  muscles.    And  these 


INSTINCT.  439 

three  psychical  states  being  habitually  connected,  must,  by 
repetition  in  countless  generations,  become  so  coherent  that 
the  special  visual  impression  will  directly  call  forth  the  mno- 
cular  actions  by  which  prey  is  seized.  Eventually,  the  sight 
of  a  small  object  in  front  will  cause  the  various  motions 
requisite  for  the  capture  of  prey. 

Here,  then,  we  see  how  one  of  the  simpler  instincts  will, 
under  the  requisite  conditions,  be  established  by  accumu- 
lated experiences.  Let  it  be  granted  that  the  more  fre- 
quently psychical  states  occur  in  a  certain  order,  the 
stronger  becomes  their  tendency  to  cohere  in  that  order, 
until  they  at  last  become  inseparable;  let  it  be  granted 
that  this  tendency  is,  in  however  slight  a  degree,  inherited, 
so  that  if  the  experiences  remain  the  same  each  successive 
generation  bequeaths  a  somewhat  increased  tendency;  and 
it  follows  that,  in  cases  like  the  one  described,  there  must 
eventually  result  an  automatic  connexion  of  nervous  actions, 
corresponding  to  the  external  relations  perpetually  ex- 
perienced. Similarly  if,  from  some  change  *in  the  en- 
vironment of  any  species,  its  members  are  frequently 
brought  in  contact  with  a  relation  having  terms  a  little 
more  involved;  if  the  organization  of  the  species  is  so  far 
developed  as  to  be  impressible  by  these  terms  in  close  suc- 
cession; then,  an  inner  relation  corresponding  to  this  new 
outer  relation  will  gradually  be  formed,  and  will  in  the  end 
become  organic.  And  so  on  in  subsequent  stages  of  pro- 
gress. 

This  of  course  is  intended  merely  as  a  rude  indication  of 
the  mode  in  which  the  general  principles  enunciated  explain 
the  development  of  instincts.  The  law  of  intelligence  being 
that  the  strengths  of  the  inner  cohesions  between  psychical 
states  must  be  proportionate  to  the  persistences  of  the 
outer  relations  symbolized;  and  the  development  of  in- 
telligence in  conformity  with  this  law  being,  in  all  cases 
of  which  we  have  direct  knowledge,  secured  by  the  one 
simple  principle  that  experience  of  the  outer  relations  pro- 


440  SPECIAL  SYNTHESIS. 

duces  the  inner  cohesions  and  makes  the  inner  cohesions 
strong  in  proportion  as  the  outer  relations  are  persistent; 
it  was  requisite  to  inquire  whether  the  intelligence  concern- 
ing whose  genesis  we  have  no  direct  knowledge,  had  pro- 
bably a  like  origin.  And  reasoning  deductively  from  the 
conditions  of  the  case,  we  conclude  that  this  same  simple 
principle  is  sufficient  to  account  for  the  facts — or  rather,  for 
a  type  of  them.  To  trace  out  the  actual  development  of 
instincts,  in  their  infinite  varieties  and  complications,  must 
ever  remain  impossible:  adequate  data  are  not  to  be  had. 
The  foregoing  is  to  be  taken  simply  as  an  adumbration  of 
the  probable  mode  of  development. 

§  197.  What  must  be  the  ulterior  results  of  this  mode 
of  development?  Assuming  some  such  process  as  that 
above  suggested  to  be  the  one  by  which  instincts  in  general 
are  evolved;  let  us  deduce  the  characteristics  of  the  evolu- 
tion regarded  in  its  ensemble,  and  see  how  far  they  agree 
with  the  actual  characteristics. 

The  progression  from  the  lower  to  the  higher  instincts  is, 
throughout,  a  progression  towards  greater  speciality  and 
complexity  of  correspondence.  The  movement  produced 
in  a  creature  having  a  rudimentary  eye,  when  an  opaque  ob- 
ject is  suddenly  passed  before  that  eye,  is  more  general  and 
more  simple  than  is  the  movement  produced  in  a  creature 
which  grasps  the  prey  passing  before  it.  In  the  first  case 
the  effect  is  produced  whatever  the  relative  position  of  the 
object,  providing  the  obscuration  be  considerable;  in  the 
second  case  it  is  produced  only  when  the  object  is  just  in 
front.  To  the  outer  relation  between  a  moving  opacity  and 
a  living  solid  body,  is  now  added  a  relation  of  position; 
and  not  only  a  relation  of  position  but  one  of  magnitude, 
since  the  effect  is  not  the  same  when  a  large  as  when  a 
small  body  is  presented.  That  is  to  say,  the  external 
phenomenon  responded  to  is  a  co-ordinated  group  of  attri- 
butes and  relations;  while  internally,  there  is  a  co-ordi-. 


INSTINCT.  441 

nated  group  of  changes — not  a  single  impression  and  a 
single  motion,  but  at  least  a  pair  of  impressions  and  a  con- 
siderable complication  of  motions.  The  correspondence  is 
alike  more  complex  and  more  special. 

Now,  that  the  evolution  of  intelligence,  if  caused  by  the 
multiplication  of  experiences,  must  follow  this  order,  is 
demonstrable  d  priori.  Phenomena  become  less  frequent 
in  proportion  as  they  become  more  complex;  and  hence^ 
the  experiences  of  them  can  never  be  so  numerous  as  are 
the  experiences  of  simple  phenomena.  The  relation  between 
a  passing  obscuration  and  a  living  body,  recurs  of  tener  than 
the  relation  between  a  certain  degree  of  obscuration  and 
danger,  or  than  the  relation  between  a  certain  other  degree 
of  obscuration  and  food.  Again,  each  of  these  relations  is 
more  general  than  the  relation  between  a  particular  size  and 
form  of  visual  impression  and  an  object  of  a  particular  class. 
And  again,  this  relation  is  more  general  than  that  between 
a  particular  size,  form,  and  colour  of  visual  impression,  and 
a  certain  species  of  that  class.  The  inevitable  corollary  is, 
that  if  inner  relations  are  moulded  to  outer  relations  by  the 
accumulation  of  experiences,  the  simpler  must  be  established 
before  the  more  complex. 

The  necessity  of  this  order  will  be  still  better  seen  on  re- 
membering that  complex  relations,  both  external  and  in- 
ternal, being  composed  of  simple  ones,  must  be  preceded  by 
simple  ones.  Before  there  can  exist  the  objective  relations 
implied  in  the  action  of  one  body  on  another,  there  must 
exist  the  objective  relations  implied  in  the  existence  of 
each  body.  And  similarly,  before  complex  subjective  rela- 
tions can  be  established  there  must  have  been  established 
the  simpler  subjective  relations  they  are  composed  of. 

Observing  that  this  inference  from  the  experience-hypo- 
thesis harmonizes  with  the  facts,  so  far  as  they  are  accessible 
to  us,  let  us  go  on  to  observe  some  important  corollaries. 

§  198.  If  simple  and  general  relations  in  the  environment 


442  SPECIAL  SYNTHESIS. 

must  be  those  most  frequently  experienced,  and  those  to 
which  the  response  first  becomes  decided;  if  environing 
relations  a  grade  less  simple  and  general  are  thus  rendered 
appreciable,  and  by  a  repeated,  though  a  less-frequently  re- 
peated, experience,  also  establish  answering  internal  rela- 
tions; and  if  this  process  slowly  extends  to  relations  suc- 
cessively more  complex  and  special,  and  less  frequent ;  then 
there  will  ultimately  be  established  in  the  organism,  nume- 
rous psychical  relations  having  different  degrees  of  cohesion. 
While  an  infinity  of  experiences  will  have  rendered  the  first 
and  simplest  of  these  psychical  relations  indissoluble ;  while 
experiences  extremely  numerous,  though  less  numerous,  may 
have  given  indissolubleness  to  psychical  relations  one  degree 
more  complex  or  two  degrees  more  complex  or  three  degrees 
more  complex;  it  is  manifest  that  among  relations  increas- 
ingly involved  and  decreasingly  frequent,  there  must  come 
a  stage  at  which  the  answering  psychical  relations  are  not 
indissoluble.  This  may  be  conveniently  illustrated  by 
symbols. 

Let  A  and  B  represent  two  attributes  of  matter  in  general 
-r— say  extension  and  resistance — to  the  constant  relation  be- 
tween which  a  responsive  relation  has  been  established  in 
the  organism.  Let  C  and  D  be  two  extremely  general  at- 
tributes of  animal  matter — say  motion  and  life — to  which 
also  there  is  a  responsive  internal  relation.  It  will  be  at 
once  understood  that  experiences  of  the  united  group  of 
attributes  A,  B,  C,  D,  recurring  as  they  do  in  every  living 
creature  met  with,  may  eventually  establish  an  answering 
connexion  of  internal  relations  that  is  practically  as  absolute 
as  the  original  ones.  It  is  also  comprehensible  that  if  the 
creatures  serving  for  prey  are  below  a  certain  size,  L,  while 
those  found  to  be  enemies  are  mostly  of  a  much  greater 
size,  M;  continued  experience  may  establish  different  or- 
ganic responses  to  the  different  groups  of  co-existent  attri- 
butes, A,  B,  C,  D,  L,  and  A,  B,  C,  D,  M.  And  it  is  not 
difficult  to  see  that  when  each  of  these  large  classes  comes 


INSTINCT.  443 

to  be  distinguishable  into  sub-classes — say  by  means  of  dif- 
ferences of  colour — the  experiences  of  the  two  groups  A  B 
C  D  L  S,  and  A  B  C  D  L  T,  and  of  the  two  groups  A 
B  C  D  M  F,  and  A  B  C  D  M  Q,  may  still  be  severally 
numerous  enough  to  make  the  answering  psychical  actions 
automatic.  But,  clearly,  along  with  more  involved  and  more 
varied  groups  there  must  eventually  come  imperfect  psychi- 
cal cohesions.  As,  by  successive  additions  of  perceived  attri- 
butes and  relations,  the  psychical  states  become  more  com- 
plex; and  as  each  more  complex  combination  of  psychical 
states  corresponding  to  a  more  special  kind  of  object  is,  by 
consequence,  less  frequently  repeated  in  experience;  it  fol- 
lows from  the  general  law  we  are  tracing  out  that  its  com- 
ponents cannot  be  so  completely  integrated.  Not  only  must 
the  clustered  internal  states  by  which  the  clustered  external 
properties  are  symbolized,  be  less  definitely  aggregated  (or 
at  any  rate  the  more  recently  added  of  them) ;  but  the  com- 
posite impression  they  form  must  have  a  smaller  power  of 
producing  the  specially  co-ordinated  motions  by  which  a  fit 
adjustment  is  made. 

The  implication  lies  on  the  surface.  If,  as  the  instincts 
rise  higher  and  higher,  they  come  to  include  psychical 
changes  that  are  less  and  less  coherent  with  their  funda- 
mental ones;  there  must  arrive  a  time  when  the  co-ordina- 
tion is  no  longer  perfectly  regular.  If  these  compound 
reflex  actions,  as  they  grow  more  compound,  also  become 
less  decided;  it  follows  that  they  will  eventually  become 
comparatively  undecided.  They  will  begin  to  lose  their 
distinctly  automatic  character.  That  which  we  call  Instinct 
will  merge  into  something  higher. 

The  facts  are  thus  rendered  comprehensible.  We  see 
that,  if  produced  by  experience,  the  evolution  of  Instinct 
must  proceed  from  the  simple  to  the  complex,  and  that  by 
a  progression  thus  wrought  out,  it  must  insensibly  pass  into 
a  higher  order  of  psyohical  action;  which  is  just  what  we 
find  it  to  do  in  the  higher  animals. 


CHAPTER  VI. 


MEMORY. 


§  199.  That  growing  complication  of  the  correspondence 
which,  as  we  have  just  seen,  necessitates  a  transition  from 
automatic  actions  to  non-automatic  actions,  brings  with  it 
a  separation  of  the  process  of  correspondence  into  parts. 
In  its  simple  form,  the  adjustment  of  certain  inner  relations 
to  certain  outer  relations  is  one  indivisible  action;  but  in 
its  complex  form,  such  adjustment  consists  of  several  stages 
admitting  of  greater  or  less  dissociation  from  one  another 
— capable  of  becoming  fragments  of  correspondences. 
Thus,  among  others,  results  the  order  of  psychical  actions 
known  as  Memory. 

While,  in  any  instinctive  act,  we  see  an  entire  process  of 
bringing  internal  relations  into  harmony  with  external 
relations.  Memory,  taken  alone,  exhibits  relations  in  con- 
sciousness which  do  not  include  any  active  adjustment 
<^f  the  organism  to  relations  in  the  environment.  Though 
those  successions  of  ideas  which  constitute  Memory,  nearly 
all  represent  past  experiences  of  the  outer  world;  yet,  as 
many  if  not  most  of  them  stand  for  past  experiences  of  the 
outer  world  that  are  fortuitously  combined,  it  is  clear  that, 
even  considered  as  fragments  of  correspondences,  they 
cannot  be  held  to  have  as  marked  a  harmony  with  the 
environment  as  have  the  homologous  parts  of  automatic 

actions.    True,  each  act  of  recollection  is  the  establishment 

444 


MEMORY.  445 

of  an  inner  relation  answering  to  some  outer  relation ;  but 
as  that  outer  relation  is  often  a  transitory  one,  the  inner 
relation  established  in  the  act  of  recollection  is  often  one 
answering  to  no  relation  now  existing  or  ever  likely  to  exist 
again;  and  in  that  sense  is  not  a  correspondence.  The 
correspondence  here  becomes  evanescent. 

From  this  it  will  probably  be  inferred  that  a  satisfactory 
account  of  Memory,  as  viewed  from  our  present  stand-point, 
is  impracticable.  The  doctrine  that  all  psychical  changes 
are  interpretable  as  incidents  of  the  correspondence  between 
the  organism  and  its  environment,  seems  to  be  at  fault. 
Besides  the  fact  that  part  of  the  psychical  changes  con- 
stituting Memory  have  reference  to  no  existing  outer  rela- 
tions, there  is  the  further  fact  that  many  trains  of  thought 
have  apparently  little  or  nothing  to  do  with  adjusting  the 
conduct  to  the  requirements.  But  though  the  position  of 
Memory  in  the  psychological  system  here  sketched  out, 
may  not  be  at  once  understood,  we  need  only  pursue  the 
synthesis  a  step  further  to  see  how  Memory  results  from 
that  same  process  of  development  by  which  Instinct,  becom- 
ing more  and  more  complicated,  finally  merges  into  the 
higher  forms  of  psychical  action. 

Some  clue  will  be  gained  on  observing  that  while,  on  the 
one  hand.  Instinct  may  be  regarded  as  a  kind  of  organized 
memory;  on  the  other  hand.  Memory  may  be  regarded  as  a 
kind  of  incipient  instinct.  The  automatic  actions  of  a  bee 
building  one  of  its  wax  cells,  answer  to  outer  relations  so 
constantly  experienced  that  they  are,  as  it  were,  organically 
remembered.  Conversely,  an  ordinary  recollection  implies 
a  cohesion  of  psychical  states  which  becomes  stronger  by 
repetition,  and  so  approximates  more  and  more  to  the  in- 
dissoluble, the  automatic,  or  instinctive  cohesions.  But 
leaving  rough  suggestions,  let  us  take  up  the  general  argu- 
ment from  the  point  reached  at  the  close  of  the  last  chapter. 

§  200.  So  long  as  the  psychical  changes  are  completely 


446  SPECIAL  SYNTHESIS. 

automatic,  Memory,  as  we  understand  it,  cannot  exist — 
there  cannot  exist  those  irregular  psychical  changes  seen  in 
the  association  of  ideas.  But  when,  as  a  consequence  of  ad- 
vancing complexity  and  decreasing  frequency  in  the  groups 
of  external  relations  responded  to,  there  arise  groups  of 
internal  relations  which  are  imperfectly  organized  and  fall 
short  of  automatic  regularity;  then,  what  we  call  Memory 
becomes  nascent.  For  the  elucidation  of  this  we  must 
again  have  recourse  to  symbols. 

As  before,  let  A  B  C  D,  represent  the  group  of  co- 
existent attributes  common  to  living  bodies  in  general.  Let 
e,  f,  g,  stand  for  the  further  attributes  distinctive  of  some 
class  of  creatures  mostly  serving  for  prey.  And  let  ^,  Jc,  be 
the  attributes  peculiar  to  some  species  of  that  class,  which, 
when  attacked,  defends  itself  in  a  particular  way;  while  /i, 
m,  are  the  somewhat  similar  attributes  peculiar  to  another 
species  whose  defence  is  a  retaliation  worse  than  the  attack. 
We  have,  then,  two  very  similar  complex  groups  of  co- 
existent attributes,  ABCDefgi^fc,  and  A  B  C  D 
e  {  g  h  m,  which,  by  the  hypothesis,  are  not  frequently 
repeated  in  experience;  but  which,  when  they  do  occur,  are 
attended  by  different  consequences.  The  attributes  A,  B,  C, 
D,  being  presented  in  every  experience  of  living  creatures, 
are  responded  to  by  automatically-connected  internal  states. 
Similarly,  e,  f ,  g,  the  attributes  of  creatures  serving  for  prey, 
being  extremely  general,  have  also  answering  internal  states 
tliat  are  automatically-connected  with  the  first  and  with 
those  motor  changes  which  the  presentation  of  prey  calls  for. 
But  ^,  fc,  and  ^,  wi,  not  recurring  so  often,  are  represented 
by  internal  states  that  are  not  organically  co-ordinated  with 
their  respective  groups,  or  with  the  motor  changes  which 
those  groups  should  produce.  Such  being  the  conditions  of 
the  case,  what  must  happen? 

In  the  first  place,  the  mere  complication  in  the  sets  of  im- 
pressions serving  as  stimuli  to  special  actions,  itself  implies 
something  like  a  nascent  Memory.    For  as,  on  the  one  hand, 


MEMORY.  447 

the  nervous  centre  by  which  any  impressions  A,  B,  C,  D, 
e,  f,  g,  A,  Tc,  are  co-ordinated,  cannot  receive  all  these 
impressions  at  absolutely  the  same  instant;  and  as,  on  the 
other  hand,  the  special  actions  to  be  produced  can  be  pro- 
duced only  by  co-operation  of  all  these  impressions;  it 
follows  that  they  must  severally  have  some  slight  per- 
sistence, so  that  the  last  may  arise  before  the  first  fades 
away. 

Not  to  dwell  on  this,  however,  let  us  now  observe  that 
since  the  states  answering  to  Ti,  fc,  and  those  answering  to 
fc,  m,  have  been  unf  requently  connected  with  their  respective 
groups  of  states  and  the  sequent  actions,  the  nervous  changes 
by  which  they  are  themselves  produced  and  by  which  they 
produce  subsequent  changes,  must  be  slow.  Psychical  states 
that  often  recur  in  a  given  order,  not  only  become  increas- 
ingly coherent  but  the  transitions  from  each  to  the  next 
become  more  and  more  rapid ;  and,  conversely,  the  cohesion 
of  psychical  states  that  have  been  rarely  connected,  is  not 
only  feeble  but  the  transitions  take  appreciable  times — a 
fact  well  exemplified  in  learning  a  language.  But  the  toler- 
ably deliberate  succession  of  psychical  states  is  one  of  the 
conditions  to  Memory.  A  remembrance  implies  a  conscious- 
ness, and  a  consciousness  implies  a  perceptible  duration. 
The  nervous  states  which  are  gone  through  instantaneously 
— as  those  by  which  we  infer  the  distances  of  the  objects  we 
look  at — do  not  enter  into  what  we  term  Memory  at  all :  we 
are  unconscious  of  them  because  they  have  no  appreciable 
persistence.  Hence,  the  occurrence  of  these  comparatively- 
slow  psychical  changes  is  a  step  towards  the  evolution  of 
Memory. 

A  further  consequence  is  now  to  be  noted.  When  either 
of  the  groups  of  attributes  ABCDefg^^,  orAB 
C  D  e  f  g  ^  «i,  is  presented,  the  set  of  impressions  A 
B  C  D  e  f  g,  produced  in  common  by  both  of  them,  and 
by  all  creatures  serving  for  prey,  tends  to  excite  the  actions 
bj]  which  prey  is  ordinarily  caught.    At  the  same  time  the 


448  SPECIAL  SYNTHESIS. 

impression  produced  by  h  k^  or  h  m,  as  the  case  may  be, 
tends  to  excite  those  modified  actions  which  occurred  in 
experience  after  it.  J^ot  only,  however,  is  the  actual  pro- 
duction of  these  modified  actions  uncertain,  from  the  ex- 
perience having  been  insufficiently  repeated,  but  either  of 
the  two  tendencies  must  be  partially  opposed  by  the  other. 
The  impression  resulting  from  the  attribute  /^,  being  com- 
mon to  both  groups,  tends  equally  to  excite  either  of  the 
modified  sets  of  actions;  while  from  h  the  incipient  effect  is 
a  particular  mode  of  attack,  and  from  m  the  incipient  effect 
is  running  away.  Hence,  one  general  and  two  special  sets  of 
actions  are  instigated;  and  from  the  balance  of  the  instiga- 
tions, it  will  often  happen  that  no  immediate  action  at  all 
ensues.  The  various  psychical  states  involved  in  each  set 
of  motions,  severally  become  nascent;  but  none  of  them 
reach  that  intensity  which  they  would  have  were  the  mo- 
tions performed.  In  the  chief  nervous  centre  the  different 
impressions  serve  as  different  motor  impulses;  and  these, 
being  severally  supplanted  by  one  another  before  they  pass 
into  actual  motor  changes,  will  each  of  them  consist  of  an 
incipient  or  faint  form  of  that  nervous  state  which  would 
have  accompanied  the  actual  motor  change  had  it  occurred. 
But  such  a  succession  of  states  constitutes  ^remembrance  of 
the  motor  changes  which  thus  become  incipient — constitutes 
a  meTnory.  To  remember  a  motion  just  made  with  the  arm, 
is  to  have  a  feeble  repetition  of  those  internal  states  which 
accompanied  the  motion — is  to  have  an  incipient  excitement 
of  those  nerves  which  were  strongly  excited  during  the 
motion.  Thus,  then,  these  nascent  nervous  excitements  that 
conflict  with  one  another,  are  really  so  many  ideas  of  the 
motor  changes  which,  if  stronger,  they  would  cause;  or 
rather,  they  are  the  objective  sides  of  those  changes  which 
are  ideas  on  their  subjective  sides.  Consequently,  Memory 
necessarily  comes  into  existence  whenever  automatic  action 
is  imperfect. 

This,  however,  is  not  all.    Besides  a  memory  of  ita  own 


MEMORY.  44,9 

movements  and  modes  of  action,  there  results  in  the  or- 
ganism a  memory  of  those  combinations  of  impressions  it 
receives  through  the  senses.  Under  its  primary  form  this 
advance  is  a  concomitant  of  the  advance  just  described.  As 
the  external  groups  of  attributes  and  relations  responded  to 
become  more  complex,  and  by  implication  more  infrequent, 
the  answering  psychical  changes  become  more  loosely  con- 
nected with  one  another  and  with  the  motor  changes  appro- 
priate to  them;  and  the  groups  of  impressions  being  less 
coherent,  a  nascent  memory  of  the  component  impressions 
becomes  possible.  But  under  its  secondary  or  derivative 
form  this  advance  is  a  far  larger  one,  as  we  shall  now 
see.  For  the  same  progress  which  gives  the 

ability  to  receive  the  complex  impressions  required  to  de- 
termine complex  actions,  gives  the  ability  to  receive  com- 
plex impressions  which  do  not  tend  to  determine  any  actions 
at  all.  Evolution  of  the  senses  and  the  nervous  system, 
while  it  makes  possible  the  discrimination  of  various  kinds 
of  enemies  and  prey,  by  the  special  combinations  of  attri- 
butes they  severally  present,  also  makes  possible  the 
discrimination  of  various  other  objects.  The  power  of  co- 
ordinating the  impressions  of  size,  form,  colours,  motions, 
which  stand  for  a  particular  animal,  is  likewise  a  power  of 
co-ordinating  the  impressions  that  stand  for  trees,  plants, 
stones,  and  surrounding  things.  Most  of  these  surrounding 
things,  however,  have  no  immediate  relations  to  the  needs 
of  the  organism — are  not  habitually  followed  by  special 
motor  changes;  and  therefore  do  not  tend  to  excite  motor 
changes.  But  while  the  clustered  psychical  states  produced 
by  the  clustered  properties  of  inanimate  objects  have  usually 
no  direct  connexions  with  the  actions,  they  have  direct 
connexions  with  one  another  of  all  degrees  of  constancy; 
and,  by  consequence,  have  all  degrees  of  the  tendency  to 
arouse  one  another.  While  the  absolutely-persistent  rela- 
tions among  external  attributes,  are  responded  to  by  in- 
separable relations  of  psychical  states;  the  others,  in  their 


450  SI-ECIAL  SYNTHESIS. 

respective  grades  of  persistence,  are  responded  to  by  psy- 
chical states  proportionate  in  their  degrees  of  cohesion. 
Hence,  of  the  impressions  produced  by  adjacent  objects 
during  the  movements  of  the  organism,  each  is  apt  to  make 
nascent  certain  other  impressions  with  which  it  has  been 
connected  in  experience — calls  up  ideas  of  such  other  im- 
pressions; that  is,  causes  a  remembrance  of  the  attributes 
previously  found  in  connexion  with  the  perceived  attributes. 
As  these  psychical  states  have  in  their  turns  been  connected 
with  others,  they  tend  to  arouse  such  others;  and  thus 
there  arises  that  succession  of  ideas,  partly  regular,  partly 
irregular,  which  we  call  Memory — regular  in  so  far  as  the 
connexions  of  external  phenomena  are  regular,  and  irregu- 
lar in  so  far  as  the  groups  of  those  phenomena  occur  irregu- 
larly in  the  environment. 

§  201.  This  truth,  that  Memory  comes  into  existence 
when  the  involved  connexions  among  psychical  states  render 
their  successions  imperfectly  automatic,  is  in  harmony  with 
the  obverse  truth,  that  as  fast  as  those  connexions  among 
psychical  states  which  we  form  in  Memory,  grow  by 
constant  repetition  automatic,  they  cease  to  be  part  of 
Memory.  We  do  not  speak  of  ourselves  as  recollecting  re- 
lations which  have  become  organically  registered.  We  re- 
collect those  relations  only  of  which  the  registration  is  in- 
complete. No  one  remembers  that  the  object  at  which  he 
looks  has  an  opposite  side ;  or  that  a  certain  modification  of 
the  visual  impression  implies  a  certain  distance;  or  that  the 
thing  he  sees  moving  about  is  a  live  animal.  To  ask  a  man 
whether  he  remembers  that  the  sun  shines,  that  fire  burns, 
tliat  iron  is  hard,  would  be  a  misuse  of  language.  Even 
the  almost  fortuitous  connexions  among  our  experiences, 
cease  to  be  classed  as  memories  when  they  have  become 
thoroughly  familiar.  Though,  on  hearing  the  voice  of  some 
unseen  person  slightly  known  to  us,  we  say  we  recollect  to 
whom  the  voice  belongs,  we  do  not  use  the  same  expression 


MEMORY.  451 

respecting  the  voices  of  those  with  whom  we  live.  The 
meanings  of  words  which  in  childhood  have  to  be  con- 
sciously recalled,  seem  in  adult  life  to  be  immediately  pre- 
sent. But  the  clearest  instance  of  the  gradual  lapse 
of  memory  into  automatic  coherence,  is  yielded  by  the 
musician.  Originally,  he  was  taught  that  each  mark  on 
the  paper  has  a  certain  name,  and  implies  that  a  particular 
key  on  the  piano  is  to  be  struck;  and  during  his  first 
lessons,  each  recurrence  of  this  mark  was  accompanied  with 
a  distinct  process  of  recollecting  which  key  on  the  piano  he 
must  strike.  By  long-continued  practice,  however,  the 
series  of  psychical  changes  that  occur  between  seeing  this 
mark  and  striking  this  key,  have  been  reduced  into  one 
almost  automatic  change.  The  visual  perception  of  the  crot- 
chet or  quaver;  the  perception  of  its  position  on  the  lines 
of  the  stave,  and  of  its  relation  to  the  beginning  of  the 
bar;  the  consciousness  of  the  place  on  the  piano  where  the 
answering  key  lies;  the  consciousness  of  the  muscular  ad- 
justments required  to  bring  the  arm,  hand,  and  finger,  into 
the  attitudes  requisite  for  touching  that  key;  the  conscious- 
ness of  the  muscular  impulse  which  will  give  a  blow  of  the 
due  strength,  and  of  the  time  during  which  the  muscles 
must  be  kept  contracted  to  produce  the  right  length  of  note 
— all  these  mental  states,  which  were  at  first  so  many  sepa- 
rate recollections,  ultimately  constitute  a  succession  so  rapid 
that  the  whole  of  them  pass  in  an  instant.  As  fast  as  they 
cease  to  be  distinct  states  of  mind — as  fast  as  they  cease  to 
fill  appreciable  places  in  consciousness,  so  fast  do  they  be- 
come automatic.  The  two  things  are  two  sides  of  the  same 
thing.  And  thus  it  happens  that  the  practised  pianist 
can  play  while  conversing  with  those  around — while  his 
memory  is  occupied  with  quite  other  ideas  than  the  mean- 
ings of  the  signs  before  him. 

Now  the  fact  that  in  ourselves  psychical  states  which  are 
originally  connected  by  the  process  we  call  recollection,  be- 
come, by  perpetual  repetition,  connected  automatically  or 
80 


462  SPECIAL  SYNTHESIS. 

instinctively,  is  manifestly  the  obverse  of  the  fact  that  as, 
in  the  development  of  the  instincts,  the  psychical  states 
grow  into  more  involved  groups  that  are  less  frequently 
repeated,  there  occur  among  them  connexions  that  are  not 
automatic,  and  memory  commences.  Our  inductive  know- 
ledge of  the  one  fact  confirms  our  deduction  of  the  other. 

§  202.  Memory,  then,  pertains  to  that  class  of  psychical 
states  which  are  in  process  of  being  organized.  It  continues 
80  long  as  the  organizing  of  them  continues,  and  disappears 
when  the  organization  of  them  is  complete.  In  the  advance 
of  the  correspondence,  each  more  complex  cluster  of  attri- 
butes and  relations  which  a  creature  acquires  the  power 
of  recognizing,  is  responded  to  at  first  irregularly  and  un- 
certainly; and  there  is  then  a  weak  remembrance.  By  mul- 
tiplication of  experiences  this  remembrance  is  made  stronger 
— the  internal  cohesions  are  better  adjusted  to  the  external 
persistences;  and  the  response  is  rendered  more  appropriate. 
By  further  multiplication  of  experiences,  the  internal  rela- 
tions are  at  last  structurally  registered  in  harmony  with  the 
external  ones;  and  so,  conscious  memory  passes  into  uncon- 
scious or  organic  memory.  At  the  same  time,  a  new  and 
still  more  complex  order  of  experiences  is  rendered  appreci- 
able. The  relations  that  occur  between  these  groups  of 
phenomena  that  have  thus  been  severally  integrated  in 
consciousness,  occupy  Memory  in  place  of  the  relations  be- 
tween the  components  of  each  group.  These  become  gradu- 
ally organized;  and,  like  the  previous  ones,  are  succeeded 
by  others  more  complex  still. 


CHAPTER  VIL 

EEASOlSr. 

§  203.  That  the  commonly-assumed  hiatus  between 
Reason  and  Instinct  has  no  existence,  is  implied  both  in  the 
argument  of  the  last  few  chapters  and  in  that  more  general 
argument  elaborated  in  the  preceding  part.  The  General 
Synthesis,  by  showing  that  all  intelligent  action  whatever  is 
the  effecting  of  correspondences  between  internal  changes 
and  external  co-existences  and  sequences,  and  by  showing 
that  this  continuous  adjustment  of  inner  to  outer  relations 
progresses  in  Space,  in  Time,  in  Speciality,  in  Generality, 
and  in  Complexity,  through  insensible  gradations;  implied 
that  the  highest  forms  of  psychical  activity  arise  little  by 
little  out  of  the  lowest,  and  cannot  be  definitely  separated 
from  them.  N^ot  only  does  the  recently-enunciated  doctrine, 
that  the  growth  of  intelligence  is  throughout  determined 
by  the  repetition  of  experiences,  involve  the  continuity  of 
Reason  with  Instinct ;  but  this  continuity  is  involved  in  the 
previously-enunciated  doctrine. 

The  impossibility  of  establishing  any  line  of  demarkation 
between  the  two  may  be  clearly  demonstrated.  If  every  in- 
stinctive action  is  an  adjustment  of  inner  relations  to  outer 
relations,  and  if  every  rational  action  is  also  an  adjustment 
of  inner  relations  to  outer  relations;  then,  any  alleged  dis- 
tinction can  have  no  other  basis  than  some  difference  in  the 
characters  of  the  relations  to  which  the  adjustments  are  made. 

j  It  must  be  that  while,  in  Instinct  the  correspondence  is  be- 
'—  453 


454  SPECIAL  SYNTHESIS. 

tween  inner  and  outer  relations  that  are  very  simple  or 
general;  in  Reason,  the  correspondence  is  between  inner 
and  outer  relations  that  are  complex,  or  special,  or  abstract, 
or  infrequent.  But  the  complexity,  speciality,  abstractness. 
and  inf requency  of  relations,  are  entirely  matters  of  degree.J 
From  a  group  of  two  co-existent  attributes,  up  through 
groups  of  three,  four,  five,  six,  seven  co-existent  attributes, 
we  may  step  by  step  ascend  to  such  involved  groups  of  co- 
existent attributes  as  are  exhibited  in  a  living  body  under  a 
particular  state  of  feeling,  or  under  a  particular  physical 
disorder.  Between  relations  experienced  every  moment  and 
delations  experienced  but  once  in  a  life,  there  are  relations 
that  occur  with  all  degrees  of  commonness.  How  then  can 
any  particular  phase  of  complexity  or  inf  requency  be  fixed 
upon  as  that  at  which  Instinct  ends  and  Reason  begins? 

From  whatever  point  of  view  regarded,  the  facts  imply 
a  gradual  transition  from  the  lower  forms  of  psychical 
action  to  the  higher.  That  progressive  complication  of  the 
instincts,  which,  as  we  have  found,  involves  a  progressive 
diminution  of  their  purely  automatic  character,  likewise  in- 
volves a  simultaneous  commencement  of  Memory  and  Rea- 
son.   But  this  joint  evolution  must  be  specifically  described. 

§  204.  When  the  correspondence  has  advanced  to  those 
environing  objects  and  acts  which  present  groups  of  attri- 
butes and  relations  of  considerable  complexity,  and  which 
occur  with  comparative  rareness — when,  consequently,  the 
repetition  of  experiences  has  been  insufficient  to  make  the 
sensory  changes  produced  by  such  groups  cohere  perfectly 
vdth  the  adapted  motor  changes — when  such  motor  changes 
and  the  impressions  that  accompany  them  simply  become 
nascent;  then,  by  implication,  there  result  ideas  of  such 
motor  changes  and  impressions,  or,  as  already  explained, 
memories  of  the  motor  changes  before  performed  under  like 
circumstances,  and  of  the  concomitant  impressions.  Did  the 
process  end  here,  there  would  be  no  manifestation  of  ration- 


REASON,  455 

ality.  But  the  process  does  not  end  here,  as  we  shall 
soon  see. 

For  though  when  the  confusion  of  a  complex  impression 
with  some  allied  one  causes  a  confusion  among  the  nascent 
motor  excitations,  there  is  entailed  a  certain  hesitation; 
and  though  this  hesitation  continues  as  long  as  these 
nascent  motor  excitations,  or  ideas  of  the  correlative  actions, 
go  on  superseding  one  another;  yet,  ultimately,  some  one 
set  of  motor  excitations  will  prevail  over  the  rest.  As  the 
groups  of  antagonistic  tendencies  aroused  will  scarcely  ever 
be  exactly  balanced,  the  strongest  group  will  at  length 
pass  into  action;  and  as  this  sequence  will  usually  be  the 
one  that  has  recurred  oftenest  in  experience,  the  action  will, 
on  the  average  of  cases,  be  the  one  best  adapted  to  the  cir- 
cumstances. But  an  action  thus  produced  is  nothing  else 
than  a  rational  action.  Each  of  the  actions  which  we  call 
rational,  presents  three  phases  answering  to  those  here  de- 
scribed : — first,  a  certain  combination  of  impressions  signify- 
ing some  combination  of  phenomena  to  which  the  organism 
is  to  be  adjusted ;  second,  an  idea  of  the  actions  before  per- 
formed under  like  conditions,  which  idea  is  a  nascent  exci- 
tation of  the  nervous  agents  before  concerned  in  such 
actions,  either  as  producers  of  them  or  as  affected  by  the 
production  of  them;  and,  third,  the  actions  themselves, 
which  are  simply  the  results  of  the  nascent  excitation  rising 
into  an  actual  excitation.  An  illustration  will  make  this 
clear.  A  snarling  dog  commonly  turns  tail  when 

a  stone  is  thrown  at  him ;  or  even  when  he  sees  the  stooping 
motion  required  for  picking  up  a  stone.  Suppose  that, 
having  often  experienced  this  sequence,  I  am  again  at- 
tacked by  such  a  dog;  what  are  the  resulting  psychical 
processes?  The  combined  impressions  produced  on  my 
senses,  and  the  state  of  consciousness  which  they  arouse, 
have  before  been  followed  by  those  motor  changes  required 
for  picking  up  and  throwing  a  stone,  and  by  those  visual 
changes  resulting  from  the  dog's  retreat.     As  these  psy- 


456  SPECIAL  SYNTHESIS. 

chical  states  have  repeatedly  succeeded  one  another  in 
experience,  they  have  acquired  some  cohesion — there  is  a 
tendency  for  the  psychical  states  excited  in  me  by  the 
snarling  dog,  to  be  followed  by  those  other  psychical  states 
that  have  before  followed  them.  In  other  words,  there  is  a 
nascent  excitation  of  the  motor  apparatus  concerned  in 
picking  up  and  throwing;  there  is  a  nascent  excitation  of 
all  the  sensory  nerves  affected  during  such  acts;  and, 
through  these,  there  is  a  nascent  excitation  of  the  visual 
nerves,  which  on  previous  occasions  received  impressions  of 
a  flying  dog.  That  is,  I  have  the  ideas  of  picking  up  and 
throwing  a  stone,  and  of  seeing  a  dog  run  away;  for  these 
that  we  call  ideas,  are  nothing  else  than  weak  repetitions  of 
the  psychical  states  caused  by  actual  impressions  and 
motions.  But  what  happens  further?  If  there  is  no  an- 
tagonist impulse — if  no  other  ideas  or  partial  excitations 
arise,  and  if  the  dog's  aggressive  demonstrations  produce 
in  me  feelings  of  adequate  vividness,  these  partial  excita- 
tions pass  into  complete  excitations.  I  go  through  the  pre- 
viously-imagined actions.  The  nascent  motor  changes 
become  real  motor  changes;  and  the  adjustment  of  inner 
relations  to  outer  relations  is  completed.  This, 

however,  is  just  the  process  which  we  saw  must  arise 
whenever,  from  increasing  complexity  and  decreasing 
frequency,  the  automatic  adjustment  of  inner  to  outer  re- 
lations becomes  uncertain  or  hesitating.  Hence  it  is  clear 
that  the  actions  we  call  instinctive  pass  gradually  into  the 
actions  we  call  rational. 

Further  proof  is  furnished  by  the  converse  fact,  that  the 
actions  we  call  rational  are,  by  long-continued  repetition, 
rendered  automatic  or  instinctive.  By  implication,  this 
lapsing  of  reason  into  instinct  was  shown  in  the  last 
chapter,  when  exemplifying  the  lapsing  of  memory  into 
instinct:  the  two  facts  are  different  aspects  of  the  same 
fact.  But  some  instances  specially  exhibiting  this  second 
aspect  may  here  be  fitly  given.  Take,  as  one, 


REASON.  457 

the  actions  gone  through  in  shaving,  or  in  tying  a 
neckerchief.  Every  man  will  remember  that  when,  as 
a  youth,  he  first  attempted  to  guide  his  hands  by 
watching  the  reflections  of  them  in  the  looking-glass, 
he  was  unable  to  move  them  rightly.  The  ordinary  con- 
nexions between  the  visual  impressions  received  from  his 
moving  fingers,  and  the  muscular  feelings  accompanying 
their  motions,  no  longer  holding  good  when  he  had  to  deal 
with  the  images  of  his  fingers,  he  was  led  to  make  move- 
ments contrary  to  those  he  intended.  Only  after  setting 
himself  to  watch  how  the  muscular  feelings  and  the  reflected 
appearances  are  related,  and  then  consciously  making  a 
certain  motion  in  expectation  of  a  certain  appearance, 
did  he  slowly  master  the  difficulty.  By  daily  practice,  how- 
ever, these  psychical  changes  have  become  so  well  co- 
ordinated, that  he  now  shaves  while  thinking  of  something 
else.  Still  more  marked  is  the  analogous  process 

that  occurs  in  the  microscopist.  Whatever  he  places  under 
the  object  glass  is  seen  inverted,  and  with  its  right  and  left 
sides  interchanged.  All  adjustments  of  the  stage  and  all 
motions  of  his  dissecting  instruments,  have  to  be  made  in 
directions  opposite  to  those  which  the  uninitiated  eye  would 
dictate.  Yet  habit  renders  this  reversed  manipulation  as 
easy  as  ordinary  manipulation — it  becomes  as  unnecessary 
for  the  microscopist  to  take  thought  how  he  shall  move 
his  hands  in  the  one  case  as  in  the  other.  The 

approximately-automatic  character  of  habitual  actions  is 
clearly  proved  when  they  are  performed,  as  they  often  are, 
inappropriately.  Any  one  accustomed  to  traverse  particular 
streets  on  his  way  to  some  place  of  business,  finds  that,  when 
intending  to  branch-off  elsewhere,  he  is  apt,  if  engaged  in 
thought,  to  follow  the  usual  route — often  for  a  long  way 
beyond  the  point  at  which  he  should  have  diverged :  the  im- 
pressions received  from  the  familiar  objects  he  passes,  cause 
him  to  make  the  ordinary  crossings  and  turnings.  In 

reading  aloud,  again,  the  law  is  well  displayed.    Originally, 


458  SPECIAL  SYNTHESIS. 

sight  of  the  letters  was  followed  by  thought  of  the  sounds; 
and  thought  of  the  sounds,  by  such  vocal  actions  as 
made  the  sounds.  But  eventually,  the  connexions  between 
visual  impressions  and  vocal  actions  grow  so  far  automatic, 
that  it  becomes  possible  to  read  aloud  sentence  after  sen- 
tence while  occupied  in  thinking  of  something  else — while 
unconscious  of  the  words  uttered  and  the  ideas  conveyed  by 
them.  In  short,  many  if  not  most  of  our  common 

daily  actions  (actions  every  step  of  which  was  originally  pre- 
ceded by  a  consciousness  of  consequences  and  was  therefore 
rational)  have,  by  perpetual  repetition,  been  rendered  more 
or  less  automatic.  The  requisite  impressions  being  made 
on  us,  the  appropriate  movements  follow;  without  memory, 
reason,  or  volition,  coming  into  play. 

§  205.  A  further  interpretation  here  becomes  possible. 
We  have  seen  that  rational  action  arises  out  of  instinctive 
action  when  this  grows  too  complex  to  be  perfectly  auto- 
matic. We  have  now  to  observe  that,  at  the  same  time,  there 
arises  that  kind  of  reasoning  which  does  not  directly  lead  to 
action — that  reasoning  through  which  the  great  mass  of 
surrounding  co-existences  and  sequences  are  known. 

As  fast  as  the  groups  of  external  attributes  and  relations 
recognized,  become  too  complex  to  be  consolidated  into 
single  psychical  states,  there  result  both  the  opportunity  and 
the  power  of  inferring  such  attributes  or  relations  belonging 
to  any  group,  as  are  not  immediately  presented.  Pure  in- 
stinct continues  so  long  as  the  stimuli  responded  to  are  made 
up  of  few  and  constant  components.  While  the  combined 
impressions  of  colour,  position,  size,  and  motion,  which 
together  stand  for  an  adjacent  object  that  can  be  seized  for 
prey,  are  alone  receivable,  the  actions  will  be  purely  auto- 
matic. But  by  the  time  that  the  organization  of  experiences 
has  given  a  power  of  appreciating  the  complicated  relations 
of  form,  of  mixed  colouring,  of  peculiar  motions,  &c.,  along 
with  the  more  general  ones  of  colour,  position,  size,  and 


REASON.  459 

motion;  the  attributes  and  relations  united  into  a  group, 
have  grown  not  only  too  numerous  to  be  all  mentally 
presented  at  the  same  instant,  but  too  numerous  to  be  all 
physicaUy  presented  at  the  same  instant.  For  the  same 
experiences  which  have  rendered  these  complex  groups  of 
attributes  cognizable,  have  also  brought  them  before  the 
senses  in  such  various  ways,  that  sometimes  one  part  of  a 
group  has  been  perceptible  and  sometimes  another  part  of 
it:  now  these  elements  of  an  animal's  form  and  markings 
and  actions  have  been  visible,  and  now  those.  Though  on 
the  average  each  experience  of  the  group  has  resembled 
previous  ones,  yet  it  has  presented  some  attributes  which 
they  did  not  present,  and  has  not  presented  others  which 
they  did  present.  Hence,  by  an  accumulation  of  such  ex- 
periences, each  complex  group  of  external  phenomena 
establishes  in  the  organism  an  answering  complex  group  of 
psychical  states,  which  has  the  peculiarity  that  it  contains 
more  states  than  were  ever  produced,  or  ever  can  be  pro- 
duced, by  any  one  presentation  of  the  external  group. 
What  must  happen  from  this?  It  must  happen  that  when, 
on  any  future  presentation  of  the  external  group,  certain  of 
these  aggregated  psychical  states  are  directly  produced  by 
the  impressions  made  on  the  senses,  various  others  of  the 
psychical  states  that  have  been  aggregated  with  them,  or 
made  coherent  to  them  by  experience,  will  become  nascent: 
the  ideas  of  one  or  more  unperceived  attributes  will  be 
aroused:  the  unperceived  attributes  will  be  inferred. 

Here,  also,  the  doctrine  enunciated  is  verified  by  the 
established  truth  of  its  obverse.  We  lately  saw  that  while, 
on  the  one  hand,  instinctive  actions  pass  into  rational  actions 
when  from  increasing  complexity  and  infrequency  they  be- 
come imperfectly  automatic;  on  the  other  hand,  rational 
actions  pass,  by  constant  repetition,  into  automatic  or  instinc- 
tive actions.  Similarly,  we  may  here  see  that  while,  on  the 
one  hand,  rational  inferences  arise  when  the  groups  of  attri- 
butes and  relations  cognized  become  such  that  the  impres- 


460  SPECIAL  SYNTHESIS. 

sions  of  them  cannot  be  simultaneously  co-ordinated ;  on  the 
other  hand,  rational  inferences  pass,  by  constant  recurrence, 
into  automatic  inferences  or  organic  intuitions.  All  ac- 
quired perceptions  exemplify  this  truth.  The  numberless 
cases  in  which  we  seem  directly  to  know  the  distances, 
forms,  solidities,  textures,  &c.,  of  the  things  around  us,  are 
cases  in  which  psychical  states  originally  answering  to  phe- 
nomena separately  perceived,  and  afterwards  connected  in 
thought  by  inference,  have,  by  repetition,  become  indis- 
solubly  united,  so  as  to  constitute  a  rational  knowledge  that 
appears  intuitive. 

Thus,  the  experience-hypothesis  furnishes  an  adequate  so- 
lution. The  genesis  of  instinct,  the  development  of  memory 
and  reason  out  of  it,  and  the  consolidation  of  rational 
actions  and  inferences  into  instinctive  ones,  are  alike  explic- 
able on  the  single  principle,  that  the  cohesion  between 
psychical  states  is  proportionate  to  the  frequency  with  which 
the  relation  between  the  answering  external  phenomena  has 
been  repeated  in  experience. 

§  206.  But  does  the  experience-hypothesis  also  explain 
the  evolution  of  the  higher  forms  of  rationality  out  of  the 
lower?  It  does.  Beginning  with  reasoning  from  particu- 
lars to  particulars — familiarly  exhibited  by  children  and  by 
domestic  animals — the  progress  to  inductive  and  deductive 
reasoning  is  similarly  unbroken,  as  well  as  similarly  deter- 
mined. And  by  the  accumulation  of  experiences  is  also 
determined  the  advance  from  narrow  generalizations  to 
generalizations  successively  wider  and  wider. 

Were  it  not  for  the  prevalent  anxiety  to  establish  some 
absolute  distinction  between  animal  intelligence  and  human 
intelligence,  it  would  be  needless  to  assign  proof  of  this. 
Even  as  it  is,  the  truth  is  so  manifest  that  under  most  of  its 
aspects  none  question  it.  Every  one  admits  that  the  infant, 
while  occupied  in  drawing  those  simplest  inferences  which 
by  and  by  become  consolidated  into  acquired  perceptions,  is 


REASON.  461  - 

exercising  no  higher  rationality  than  the  dog  that  recognizes 
his  own  name,  the  different  members  of  the  household,  and 
the  hours  of  meals.  Every  one  must  also  admit  that  the 
steps  by  which  these  simplest  inferences  of  the  infant  pass 
into  those  inferences  of  high  complexity  drawn  in  adult  life, 
are  so  gradual  that  it  is  impossible  to  mark  the  successive 
steps:  no  one  can  name  that  day  in  any  human  life  when 
the  alleged  division  between  special  and  general  conclusions 
was  crossed.  Hence,  every  one  is  bound  to  admit  that  as  the 
rationality  of  an  infant  is  no  higher  than  that  of  a  dog,  if 
so  high;  and  as,  from  the  rationality  of  the  infant  to  that 
of  the  man  the  progress  is  through  gradations  which  are  in- 
finitesimal; there  is  also  a  series  of  infinitesimal  gradations 
through  which  brute  rationality  may  pass  into  human  ration- 
ality. Further,  it  must  be  admitted  that  as  the  assimilation 
of  experiences  of  successively-increasing  complexity,  sufiices 
for  the  unfolding  of  reason  in  the  individual  human  being; 
so  must  it  sufiice  for  the  evolution  of  reason  in  general. 

Equally  clear  is  the  argument  from  the  history  of  civiliza- 
tion or  from  the  comparison  of  existing  races  of  men.  That 
there  is  an  immense  difference  in  abstractness  between  the 
reasonings  of  the  aboriginal  races  who  peopled  Britain,  and 
the  reasonings  of  the  Bacons  and  Newtons  who  have  de- 
scended from  them,  is  a  trite  remark.  That  the  Papuan  can- 
not draw  inferences  approaching  in  complexity  to  those  daily 
drawn  by  European  sa/oants,  is  no  less  a  platitude.  Yet  no 
one  alleges  an  absolute  distinction  between  our  faculties  and 
those  of  our  remote  ancestors,  or  between  the  faculties  of 
civilized  men  and  those  of  savages.  Fortunately,  there  are 
records  showing  that  the  advance  towards  conceptions  of 
great  complication  and  high  generality,  has  taken  place 
by  slow  steps — by  natural  growth.  Let  us  glance  at 
them.  Simple  numeration  existed  before  arithmetic; 

arithmetic  before  algebra;  algebra  before  the  infinitesimal 
calculus;  and  the  more  special  forms  of  the  infinitesimal 
calculus  before  its  more  general  forms.     The  law  of  the 


462  SPECIAL  SYNTHESIS. 

scales  was  known  before  the  general  law  of  the  lever  was 
known;  the  law  of  the  lever  was  known  before  the  laws  of 
composition  and  resolution  of  forces  were  known ;  and  these 
were  known  before  the  laws  of  motion  under  their  universal 
forms  were  known.  From  the  ancient  doctrine  that  the 
curve  in  which  the  sun,  the  moon,  and  each  of  the  planets, 
moves,  is  a  circle  (a  perfectly  simple  and  constant  figure); 
to  the  doctrine  taught  by  Kepler,  that  each  member  of  the 
planetary  system  describes  an  ellipse  (a  much  less  simple  and 
constant  figure) ;  and  afterwards  to  the  doctrine  taught  by 
Newton,  that  the  curve  described  by  every  heavenly  body 
is  some  conic  section  (a  still  less  simple  and  constant 
figure);  the  advance  in  generality,  in  complexity,  in  ab- 
stractness,  is  manifest.  Numerous  like  illustrations  are 
furnished  by  Physics,  by  Chemistry,  by  Physiology:  all  of 
them  showing,  in  common  with  the  foregoing  ones, 
that  the  advance  has  been  gradual,  and  that  each  more 
general  relation  has  become  known  through  the  experience 
of  relations  a  degree  less  general.  If,  then,  we  have 

proof  that  in  the  course  of  civilization  there  has  been  an 
advance  from  rational  cognitions  of  a  low  order  of  generality 
to  those  of  a  high  order  of  generality,  brought  about  solely 
by  the  accumulation  of  experiences;  if  this  advance  is  as 
great  as  that  from  the  higher  forms  of  brute  rationality  to 
the  lower  forms  of  human  rationality  (which  no  one  who 
compares  the  generalizations  of  a  Hottentot  with  those  of 
La  Place  can  deny);  it  is  a  legitimate  conclusion  that 
the  accumulation  of  experiences  suffices  to  account  for  the 
evolution  of  all  rationality  out  of  its  simplest  forms.  The 
distinction,  contended  for  by  Whately,  between  special 
reasoning  and  general  reasoning,  is  untenable.  Generality 
is  entirely  a  thing  of  degree;  and  unless  it  be  asserted  that 
the  rational  faculty  of  the  cultivated  European  is  essentially 
different  from  that  of  a  savage  or  a  child,  it  cannot  con- 
sistently be  asserted  that  there  is  any  essential  difference 
between  brute  reason  and  human  reason. 


REASON.  463 

§  207.  To  complete  the  argument  it  needs  but  to  show, 
by  a  special  synthesis,  that  the  establishment  of  every 
generalization,  simple  or  complex,  concrete  or  abstract,  is 
definitely  explicable  in  conformity  with  the  principle  hither- 
to traced.  The  general  law  that  the  cohesion  of  psychical 
states  is  determined  by  the  frequency  with  which  they  have 
followed  one  another  in  experience,  affords  a  satisfactory 
solution  of  the  highest  as  of  the  lowest  psychological  phe- 
nomena. When  treating  of  the  integration  of  correspon- 
dences, something  was  done  towards  showing  that  the  for- 
mation of  the  most  extended  generalizations  does  not  differ 
in  method  from  the  formation  of  the  simplest  perceptions; 
but  here,  this  may  be  more  definitely  shown. 

As  an  instance  let  us  take  the  discovery  of  the  relation 
between  degree  of  evolution  of  the  nervous  system  and  de- 
gree of  intelligence.  Originally,  no  such  relation  was  recog- 
nized or  was  suspected.  It  was  known  that  certain  creatures 
have  more  sagacity  than  others.  It  was  known  that  certain 
creatures  have  larger  heads  than  others.  To  some  it  was 
known  that  the  larger  heads  commonly  contain  larger 
masses  of  soft  whitish  matter.  But  the  causal  connexions 
among  these  traits  were  obscured  by  other  connexions.  In- 
telligent creatures  were  seen  to  have  various  other  charac- 
teristics besides  large  brains.  Most  of  them  are  four- 
legged;  most  of  them  are  covered  with  fur;  most  of  them 
have  teeth.  And  creatures  having  large  brains  were  seen  to 
have  other  characteristics  than  that  of  intelligence:  as 
strength,  length  of  life,  viviparousness.  Hence,  there  was 
at  first  no  reason  why  height  of  intelligence  and  extent  of 
nervous  development,  should  be  thought  of  together. 
What,  then,  was  needed  to  establish  a  mental  connexion 
between  them?  Nothing  but  an  accumulation  of  ex- 
periences; or,  as  we  say — a  multiplying  of  observations. 
That  the  rationale  of  this,  and  its  conformity  to  the  general 
law,  may  be  understood,  let  us  have  recourse  to  symbols. 
Let  A  stand  for  the  known  characteristic,  intelligence. 


464  SPECIAL  SYNTHESIS. 

And  let  us  put  X  to  represent  the  unknown  characteristic 
on  which  it  is  dependent — a  developed  nervous  system.  Now 
A  is  found  along  with  many  varieties  of  size,  form,  colour, 
structure,  habit,  &c. ;  and  X  co-exists  with  this,  that,  and 
the  other  peculiarity,  besides  intelligence.  That  is  to  say, 
there  are  many  different  groups  of  attributes  variously  as- 
sociated with  A  and  X,  and  by  which  the  relation  of  A  to 
X  is  disguised;  or,  to  continue  the  symbols — there  are 
groups,  BCDXLFZA,  PLFAQNXY,  EDZR 
X  B  A  O  Y,  and  so  on,  in  countless  combinations.  But 
now  if,  other  things  being  equal,  the  cohesion  of  psychical 
states  is  proportionate  to  the  number  of  times  they  have 
been  connected  in  experience,  what  must  result  in  the 
minds  of  those  who  are  continually  impressed  with  groups 
of  attributes  which,  differing  as  they  do  in  other  respects, 
are  alike  in  presenting  the  relation  A  to  X?  As  the  rela- 
tion of  A  to  X  is  constant;  as  the  relations  of  A  to  any 
other  attribute,  and  of  X  to  any  other  attribute,  are  not  con- 
stant; as,  consequently,  the  relation  of  A  to  X  occurs  with 
greater  frequency  than  the  relation  of  A  to  anything  else, 
or  of  X  to  anything  else;  it  follows  from  the  general 
law  that  the  psychical  states  answering  to  A  and  X,  will 
become  more  coherent  to  each  other  than  either  is  to  the 
rest  of  the  states  with  which  they  occur — there  will  even- 
tually arise  a  tendency  for  A  to  call  up  X,  and  for  X  to  call 
up  A.  In  other  words,  A  and  X  will  be  connected  in  thought 
as  attributes  that  constantly  co-exist;  and  so  will  be  esta- 
blished the  generalization  that  the  degree  of  intelligence 
varies  as  the  development  of  the  nervous  system. 

Manifestly,  the  same  reasoning  holds  however  compli- 
cated the  relations,  and  however  greatly  obscured.  In- 
volved and  varied  as  may  be  the  phenomena  to  be  gene- 
ralized, if  there  has  already  been  reached  that  grade  of 
intelligence  required  for  cognition  of  the  complex  terms  of 
the  relation  common  to  them;  then,  repeated  experiences 
will  eventually  generalize  the  relation,  in  virtue  of  that 


REASON.  465 

same  simple  law  of  psychical  changes  which  we  have  found 
sufficient  to  explain  the  lower  phenomena  of  intelligence. 

§  208.  Here  seems  to  be  the  fittest  place  for  pointing  out 
how  the  general  doctrine  that  has  been  developed,  supplies 
a  reconciliation  between  the  experience-hypothesis  as  com- 
monly interpreted,  and  the  hypothesis  which  the  tran- 
scendentalists  oppose  to  it.* 

•  In  the  first  edition  of  this  work  there  here  followed  a  paragraph 
which  is  no  longer  required,  nor  can  indeed  be  properly  embodied  in  the 
text — a  paragraph  expressing  a  belief  in  the  natural  genesis  of  organic 
forms,  in  contrast  with  the  current  belief  in  their  supernatural  genesis. 
But  while  this  paragraph  is  now  needless,  it  formed  a  needful  part  of  the 
argument  as  originally  worked  out;  and  I  here  append  it  for  this  reason, 
as  well  as  for  the  purpose  of  indicating  the  view  I  held  on  the  question  of 
the  origin  of  species  at  the  time  when  the  first  edition  of  this  work  was 
published  in  1855.  The  paragraph  is  intentionally  reproduced  without 
verbal  amendments  or  changes  of  any  kind. 

"  As  most  who  have  read  thus  far  will  have  perceived,  both  the  general 
argument  unfolded  in  the  synthetical  divisions  of  this  work,  and  many  of 
the  special  arguments  by  which  it  has  been  supported,  imply  a  tacit  adhe- 
sion to  the  development  hypothesis— the  hypothesis  that  Life  in  its  multi- 
tudinous and  infinitely-varied  embodiments,  has  arisen  out  of  the  lowest 
and  simplest  beginnings,  by  steps  as  gradual  as  those  which  evolve  a  homo- 
geneous microscopic  germ  into  a  complex  organism.  This  tacit  adhesion, 
which  the  progress  of  the  argument  has  rendered  much  more  obvious  than 
I  anticipated  it  would  become,  I  do  not  hesitate  to  acknowledge.  Not, 
indeed,  that  I  adopt  the  current  edition  of  the  hypothesis.  Ever 
since  the  recent  revival  of  the  controversy  of  '  law  versus  miracle,'  I  have 
not  ceased  to  regret  that  so  unfortunate  a  statement  of  the  law  should 
have  been  given — a  statement  quite  irreconcilable  with  very  obvious  truths, 
and  one  that  not  only  suggests  insurmountable  objections,  but  makes  over 
to  opponents  a  vast  series  of  facts  which,  rightly  interpreted,  would  tell 
with  great  force  against  them,  [This  referred  to  the  Vestiges  of  the  Natural 
History  of  Creation.]  What  may  be  a  better  statement  of  the  law,  this  is 
not  the  place  to  inquire.  It  must  suffice  to  enunciate  the  belief  that  Life 
under  all  its  forms  has  arisen  by  a  progressive,  unbroken  evolution;  and 
through  the  immediate  instrumentality  of  what  we  call  natural  causes. 
That  this  is  an  hypothesis,  I  readily  admit.  That  it  may  never  be  anything 
more,  seems  probable.  That  even  in  its  most  defensible  shape  there  are 
serious  difficulties  in  its  way,  I  cheerfully  acknowledge :  though,  consider- 
ing the  extreme  complexity  of  the  phenomena ;  the  entire  destruction  of 


466  SPECIAL  SYNTHESIS. 

The  universal  law  that,  other  things  equal,  the  cohesion 
of  psychical  states  is  proportionate  to  the  frequency  with 
which  they  have  followed  one  another  in  experience, 
supplies  an  explanation  of  the  so-called  "  forms  of  thought," 
as  soon  as  it  is  supplemented  by  the  law  that  habitual 
psychical  successions  entail  some  hereditary  tendency  to 
such  successions,  which,  under  persistent  conditions,  will 
become  cumulative  in  generation  after  generation.  We 
saw  that  the  establishment  of  those  compound  reflex  actions 
called  instincts,  is  comprehensible  on  the  principle  that 
inner  relations  are,  by  perpetual  repetition,  organized  into 
correspondence  with  outer  relations.  We  have  now  to 
observe  that  the  establishment  of  those  consolidated,  those 
indissoluble,  those  instinctive  mental  relations  constituting 
our  ideas  of  Space  and  Time,  is  comprehensible  on  the  same 
principle.  For  if  even  to  external  relations  that 

are  often  experienced  during  the  life  of  a  single  organism, 
answering  internal  relations  are  established  that  become 
next  to  automatic — if  such  a  combination  of  psychical 
changes  as  that  which  guides  a  savage  in  hitting  a  bird 

the  earlier  part  of  the  evidence ;  the  fragmentary  and  obscure  character  of 
that  which  remains ;  and  the  total  lack  of  information  respecting  the  in- 
finitely-varied and  involved  causes  that  have  been  at  work ;  it  would 
be  strange  were  there  not  such  difficulties.  Imperfect  as  it  is,  how- 
ever, the  evidence  in  favour  appears  to  me  greatly  to  preponderate  over 
the  evidence  against.  Save  for  those  who  still  adhere  to  the  Hebrew 
myth,  or  to  the  doctrine  of  special  creations  derived  from  it,  there  is  no 
alternative  but  this  hypothesis  or  no  hypothesis.  The  neutral  state  of 
having  no  hypothesis,  can  be  completely  preserved  only  so  long  as  the  con- 
flicting evidences  appear  exactly  balanced :  such  a  state  is  one  of  unstable 
equilibrium,  which  can  hardly  be  permanent.  For  myself,  finding  that 
there  is  «o  positive  evidence  of  special  creations,  and  that  there  is  some 
positive  evidence  of  evolution — alike  in  the  history  of  the  human  race,  in 
the  modifications  undergone  by  all  organisms  under  changed  conditions, 
in  the  development  of  every  living  creature — I  adopt  the  hypothesis 
until  better  instructed :  and  I  see  the  more  reason  for  doing  this,  in  the 
facts,  that  it  appears  to  be  the  unavoidable  conclusion  pointed  to  by  the 
foregoing  investigations,  and  that  it  furnishes  a  solution  of  the  contro- 
versy between  the  disciples  of  Locke  and  those  of  Kant." 


KEASON.  467 

with  an  arrow,  becomes,  by  constant  repetition,  so  organ- 
ized as  to  be  performed  almost  without  thought  of  the  pro- 
cesses of  adjustment  gone  through — and  if  skill  of  this  kind 
is  so  far  transmissible  that  particular  races  of  men  become 
characterized  by  particular  aptitudes,  which  are  nothing 
else  than  partially-organized  psychical  connexions;  then, 
if  there  exist  certain  external  relations  which  are  expe- 
rienced by  all  organisms  at  all  instants  of  their  waking  lives 
— relations  which  are  absolutely  constant,  absolutely  uni- 
versal— there  will  be  established  answering  internal  rela- 
tions that  are  absolutely  constant,  absolutely  universal. 
Such  relations  we  have  in  those  of  Space  and  Time.  The 
organization  of  subjective  relations  adjusted  to  these  ob- 
jective relations  has  been  cumulative,  not  in  each  race  of 
creatures  only,  but  throughout  successive  races  of  creatures; 
and  such  subjective  relations  have,  therefore,  become  more 
consolidated  than  all  others.  Being  experienced  in  every 
perception  and  every  action  of  each  creature,  these  con- 
nexions among  outer  existences  must,  for  this  reason  too, 
be  responded  to  by  connexions  among  inner  feelings,  that 
are,  above  all  others,  indissoluble.  As  the  substrata  of  all 
other  relations  in  the  non-ego,  they  must  be  responded  to 
by  conceptions  that  are  the  substrata  of  all  other  relations 
in  the  ego.  Being  the  constant  and  infinitely-repeated  ele- 
ments of  thought,  they  must  become  the  automatic  ele- 
ments of  thought — the  elements  of  thought  which  it  is 
impossible  to  get  rid  of — the  "  forms  of  intuition." 

Such,  it  seems  to  me,  is  the  only  possible  reconciliation 
between  the  experience-hypothesis  and  the  hypothesis  of 
the  transcendentalists ;  neither  of  which  is  tenable  by  itself. 
Insurmountable  difficulties  are  presented  by  the  Kantian 
doctrine  (as  we  shall  hereafter  see);  and  the  antagonist 
doctrine,  taken  alone,  presents  difficulties  that  are  equally 
insurmountable.  To  rest  with  the  unqualified  assertion  that, 
antecedent  to  experience,  the  mind  is  a  blank,  is  to  ignore 
the  questions — whence  comes  the  power  of  organizing  expe- 
81 


468  SPECIAL  SYNTHESIS. 

riences?  whence  arise  the  different  degrees  of  that  power 
possessed  by  different  races  of  organisms,  and  different 
individuals  of  the  same  race?  If,  at  birth,  there  exists 
nothing  but  a  passsive  receptivity  of  impressions,  why 
is  not  a  horse  as  educable  as  a  man?  Should  it  be 
said  that  language  makes  the  difference,  then  why  do 
not  the  cat  and  the  dog,  reared  in  the  same  household, 
arrive  at  equal  degrees  and  kinds  of  intelligence?  Under- 
stood in  its  current  form,  the  experience-hypothesis  implies 
that  the  presence  of  a  definitely-organized  nervous  system 
is  a  circumstance  of  no  moment — a  fact  not  needing  to  be 
taken  into  account!  Yet  it  is  the  all-important  fact — the 
fact  to  which,  in  one  sense,  the  criticisms  of  Liebnitz  and 
others  pointed — the  fact  without  which  an  assimilation  of 
experiences  is  inexplicable.  Throughout  the  animal 

kingdom  in  general,  the  actions  are  dependent  on  the 
nervous  structure.  The  physiologist  shows  us  that  each 
reflex  movement  implies  the  agency  of  certain  nerves  and 
ganglia;  that  a  development  of  complicated  instincts  is 
accompanied  by  complication  of  the  nervous  centres  and 
their  commissural  connexions;  that  the  same  creature  in 
different  stages,  as  larva  and  imago  for  example,  changes  its 
instincts  as  its  nervous  structure  changes;  and  that  as  we 
advance  to  creatures  of  high  intelligence,  a  vast  increase  in 
the  size  and  in  the  complexity  of  the  nervous  system  takes 
ilacp.  What  is  the  obvious  inference?  It  is  that  the 
ability  to  co-ordinate  impressions  and  to  perform  the  appro- 
priate actions,  always  implies  the  pre-existence  of  certain 
nerves  arranged  in  a  certain  way.  What  is  the  meaning  of 
the  human  brain?  It  is  that  the  many  established  rela- 
tions among  its  parts,  stand  for  so  many  established  rela- 
tions among  the  psychical  changes.  Each  of  the  constant 
connexions  among  the  fibres  of  the  cerebral  masses,  answers 
to  some  constant  connexion  of  phenomena  in  the  experi- 
ences of  the  race.  Just  as  the  organized  arrangement  sub- 
sisting between  the  sensory  nerves  of  the  nostrils  and  the 


REASON.  469 

motor  nerves  of  the  respiratory  muscles,  not  only  makes 
possible  a  sneeze,  but  also,  in  the  newly-born  infant,  implies 
sneezings  to  be  hereafter  performed;  so,  all  the  organized 
arrangements  subsisting  among  the  nerves  of  the  infant's 
brain,  not  only  make  possible  certain  combinations  of  im- 
pressions, but  also  imply  that  such  combinations  will  here- 
after be  made — imply  that  there  are  answering  combina- 
tions in  the  outer  world — imply  a  preparedness  to  cognize 
these  combinations — imply  faculties  of  comprehending  them. 
It  is  true  that  the  resulting  compound  psychical  changes, 
do  not  take  place  with  the  same  readiness  and  automatic 
precision  as  the  simple  reflex  action  instanced — it  is  true 
that  some  individual  experiences  seem  required  to  establish 
them.  But  while  this  is  partly  due  to  the  fact  that  these 
combinations  are  highly  involved,  extremely  varied  in  their 
modes  of  occurrence,  made  up  therefore  of  psychical  rela- 
tions less  completely  coherent,  and  hence  need  further  repe- 
titions to  perfect  them;  it  is  in  a  much  greater  degree  due 
to  the  fact  that  at  birth  the  organization  of  the  brain  is  in- 
complete, and  does  not  cease  its  spontaneous  progress  for 
twenty  or  thirty  years  afterwards.  Those  who  contend  that 
knowledge  results  wholly  from  the  experiences  of  the  indi- 
vidual, ignoring  as  they  do  the  mental  evolution  which 
accompanies  the  autogenous  development  of  the  nervous 
system,  fall  into  an  error  as  great  as  if  they  were  to 
ascribe  all  bodily  growth  and  structure  to  exercise,  for- 
getting the  innate  tendency  to  assume  the  adult  form. 
Were  the  infant  bom  with  a  full-sized  and  completely- 
constructed  brain,  their  position  would  be  less  untenable. 
But,  as  the  case  stands,  the  gradually-increasing  intelli- 
gence displayed  throughout  childhood  and  youth,  is  more 
attributable  to  the  completion  of  the  cerebral  organization, 
than  to  the  individual  experiences — a  truth  proved  by  the 
fact  that  in  adult  life  there  is  sometimes  displayed  a  high 
endowment  of  some  faculty  which,  during  education,  was 
never  brought  into  play.    Doubtless,  experiences  received 


470  SPECIAL  SYNTHESIS. 

hy  the  individual  furnish  the  concrete  materials  for  all 
thought.  Doubtless,  the  organized  and  semi-organized 
arrangements  existing  among  the  cerebral  nerves,  can  give 
no  knowledge  until  there  has  been  a  presentation  of  the 
external  relations  to  which  thej  correspond.  And  doubt- 
less, the  child's  daily  observations  and  reasonings  aid  the 
formation  of  those  involved  nervous  connexions  that  are  in 
process  of  spontaneous  evolution;  just  as  its  daily  gambols 
aid  the  development  of  its  limbs.  But  saying  this  is  quite 
a  different  thing  from  saying  that  its  intelligence  is  wholly 
prodttced  by  its  experiences.  That  is  an  utterly  inadmis- 
sible doctrine — a  doctrine  which  makes  the  presence  of  a 
brain  meaningless — a  doctrine  which  makes  idiotcy  unac- 
countable. 

In  the  pense,  then,  that  there  exist  in  the  nervous  system 
certain  pre-establishe  1  relations  answering  to  relations  in 
the  environment,  there  is  truth  in  the  doctrine  of  "  forms  of 
intuition  " — not  the  truth  which  its  defenders  suppose,  but 
a  parallel  truth.  Corresponding  to  absolute  external  rela- 
tions, there  are  established  in  the  structure  of  the  nervous 
system  absolute  internal  relations — relations  that  are  poten- 
tially present  before  birth  in  the  shape  of  definite  nervous 
connexions;  that  are  antecedent  to,  and  independent  of, 
individual  experiences;  and  that  are  automatically  dis- 
closed along  with  the  first  cognitions.  And,  as  here  un- 
derstood, it  is  not  only  these  fundamental  relations  which 
are  thus  pre-determined ;  but  also  hosts  of  other  relations 
of  a  more  or  less  constant  kind,  which .  are  congenitally 
represented  by  more  or  less  complete  nervous  connex- 
ions. But  these  pre-determined  internal  relations, 
though  independent  of  the  experiences  of  the  individual, 
are  not  independent  of  experiences  in  general:  they  have 
been  determined  by  the  experiences  of  preceding  organisms. 
The  corollary  here  drawn  from  the  general  argument  is, 
that  the  human  brain  is  an  organized  register  of  infinitely- 
utraierous  experiences  received  during  the  evolution  of  life. 


REASON.  471 

or  rather,  during  tlie  evolution  of  that  series  of  organisms 
through  which  the  human  organism  has  been  reached.  The 
effects  of  the  most  uniform  and  frequent  of  these  experiences 
have  been  successively  bequeathed,  principal  and  interest; 
and  have  slowly  amounted  to  that  high  intelligence  which 
lies  latent  in  the  brain  of  the  infant — which  the  infant  in 
after  life  exercises  and  perhaps  strengthens  or  further  com- 
plicates— and  which,  with  minute  additions,  it  bequeaths  to 
future  generations.  And  thus  it  happens  that  the  European 
inherits  from  twenty  to  thirty  cubic  inches  more  brain  than 
the  Papuan.  Thus  it  happens  that  faculties,  as  of  music, 
which  scarcely  exist  in  some  inferior  human  races,  become 
congenital  in  superior  ones.  Thus  it  happens  that  out  of 
savages  unable  to  count  up  to  the  number  of  their  fingers, 
and  speaking  a  language  containing  only  nouns  and  verbs, 
arise  at  length  our  Newtons  and  Shakspeares. 


CHAPTER  Yin. 


THE    FEELINQ8. 


§  209.  The  assertion  that  those  psychical  states  which  we 
class  as  Feelings,  are  involved  with,  and  inseparable  from, 
those  which  we  class  as  intellectual  processes,  seems  a  con- 
tradiction to  direct  internal  perceptions.  It  will,  indeed,  be 
at  once  admitted  that  intellectual  processes  cannot  be  sepa- 
rated from  epi-peripheral  feelings,  real  or  ideal ;  since,  inva- 
riably, these  are  either  the  immediate  terms,  or  the  ulti- 
mate components  of  the  terms,  between  which  relations  are 
established  in  every  cognition.  But  while  all  will  grant  that 
the  feelings  initiated  in  us  by  the  forces  of  the  external 
world,  are,  in  their  presentative  or  representative  forms,  the 
indispensable  materials  of  thought,  and  that  therefore  to 
this  extent  intellect  and  feeling  cannot  be  parted;  many 
will  demur  to  the  proposition  that  feelings  of  the  ento- 
peripheral  and  central  classes  are  not  separable  from  intel- 
lectual processes. 

Some  approach  towards  a  right  comprehension  of  the 
matter,  will  be  gained  by  recalling  certain  leading  conclu- 
sions set  down  among  the  Inductions  of  Psychology.  We 
saw  that  Mind  is  composed  of  feelings  and  the  relations  be- 
tween feelings.  We  saw  that  the  feelings  are  primarily 
divisible  into  the  centrally-initiated  and  the  peripherally- 
initiated;  which  last  are  re-divisible  into  those  which  are 
initiated  at  the  outer  surface  of  the  body  and  those  which 

473 


THE  FEELINGS.  473 

are  initiated  within  the  body.  On  comparing  these  three 
great  orders  of  feelings,  we  found  that  whereas  the 
epipheripheral  are  rational  to  a  very  great  extent,  the 
entoperipheral,  and  still  more  the  central,  have  but  small 
aptitudes  for  entering  into  relations.  Hence,  by  implication, 
it  was  shown  that  the  relational  element  of  Mind  is  in  no  case 
absent.  But  the  relational  element  of  Mind  is  the  intellec- 
tual element.  Obviously,  then,  no  kind  of  feeling,  sensa- 
tional or  emotional,  can  be  wholly  freed  from  the  intellectual 
element. 

Further,  this  conclusion  is  implied  by  the  argument  ela- 
borated in  the  foregoing  chapters.  If  all  mental  phenomena 
are  incidents  of  the  correspondence  between  the  organism 
and  its  environment;  and  if  this  correspondence  passes  in- 
sensibly from  its  lowest  to  its  highest  forms;  then,  we  may 
be  certain,  d  priori,  that  no  orders  of  Feelings  can  be  com- 
pletely disentangled  from  other  phenomena  of  conscious- 
ness. We  may  infer  that  they  must  arise  gradually  out  of 
the  lower  forms  of  psychical  action,  by  steps  such  as  lead 
to  the  higher  forms  of  psychical  action  already  traced  out; 
and  that  they  must  constitute  another  aspect  of  these.  This 
is  just  what  we  shall  find. 

§  210.  Before  proceeding  to  the  synthetic  interpretation, 
it  may  be  well  to  remark  that  even  in  our  ordinary  experi- 
ences, the  impossibility  of  dissociating  the  psychical  states 
classed  as  intellectual  from  those  seemingly  most  unlike 
psychical  states  classed  as  emotional,  may  be  discerned. 
While  we  continue  to  compare  such  extreme  forms  of  the 
two  as  an  inference  and  a  fit  of  anger,  we  may  fancy  that 
they  are  entirely  distinct.  But  if  we  examine  intermediate 
modes  of  consciousness,  we  shall  quickly  find  some  which 
are  both  cognitive  and  emotive.  Take 

the  state  of  mind  produced  by  seeing  a  beautiful  statue. 
Primarily,  this  is  a  co-ordination  of  the  visual  impressions 
which  the  statue  gives,  resulting  in  a  consciousness  of  what 


474  SPECIAL  SYNTHESIS. 

they  mean;  and  this  we  call  a  purely  intellectual  act.  But 
usually  this  act  cannot  be  performed  without  some  pleasur- 
able feeling  of  the  emotional  order.  Should  it  be  said  that 
this  emotion  arises  from  the  many  ideas  associated  with  the 
human  form,  the  rejoinder  is,  that  though  these  aid  in  its 
production,  it  cannot  be  altogether  so  accounted  for;  seeing 
that  we  feel  a  kindred  pleasure  on  contemplating  a  fine 
building.  If  it  be  urged  that,  even  in  this  case,  collateral 
states  of  consciousness  are  induced  which  suffice  to  explain 
the  emotion,  then,  whence  results  the  gratification  given  on 
looking  at  a  simple  curve — an  ellipse  or  parabola?  The 
manifest  difficulty  in  disentangling  the  cognitive  from  the 
emotive  in  these  cases,  becomes,  in  other  cases,  an  impossi- 
bility. Not  only  does  the  state  of  consciousness  produced 
by  a  melody  show  us  cognition  and  emotion  inextricably 
entangled,  but  the  state  of  consciousness  produced  by  a 
single  beautiful  tone  does  so.  Not  only  is  a  combination  of 
colours,  as  in  a  landscape,  productive  of  a  pleasurable  feeling 
beyond  that  due  to  mere  sensations;  but  there  is  pleasure 
accompanying  the  perception  of  even  one  colour,  when  of 
great  purity  or  brilliance.  Nay,  the  touch  of  a  perfectly 
smooth  or  soft  surface  causes  an  agreeable  consciousness. 
In  all  these  cases  the  simple  distinct  feeling  directly  aroused 
by  the  outer  agent,  is  joined  with  some  compound  vague 
feeling  indirectly  aroused.    (See  §  128.) 

Otherwise  put,  the  matter  stands  thus.  The  materials 
dealt  with  in  every  cognitive  process  are  either  sensations  or 
the  representations  of  them.  These  sensations,  and  by  im- 
plication the  representations  of  them,  are  habitually  in  some 
degree  agreeable  or  disagreeable.  Hence,  only  in  those  rare 
cases  in  which  both  its  terms  and  its  remote  associations  are 
absolutely  indifferent,  can  an  act  of  cognition  be  abso- 
lutely free  from  emotion.  Conversely,  as  every  emotion 
involves  the  presentation  or  representation  of  objects  and 
actions;  and  as  the  perceptions,  and  by  implication  the 
recollections,  of  objects  and  actions,  all  imply  cognitions; 


THE  FEELINGS.  475 

it  follows  that  no  emotion  can  be  absolutely  free  from  cog- 
nition. 

§  211.  The  relation  between  intelligence  and  feeling  will 
be  most  clearly  understood  on  studying  the  relation  between 
perception  and  sensation,  which  are  the  simplest  forms  of 
the  two. 

Every  sensation,  to  be  known  as  one,  must  be  perceived; 
and  must  so  be  in  one  respect  a  perception.  Every  percep- 
tion must  be  made  up  of  combined  sensations;  and  must  so 
be  in  one  respect  sensational.  But  though  they  have  the 
same  essential  elements,  these  elements  are  not  similarly 
dominant  in  the  two.  In  sensation,  consciousness  is  occu- 
pied with  certain  affections  of  the  organism.  In  percep- 
tion, consciousness  is  occupied  with  the  relations  among 
those  affections.  Sensations  are  primary  undecomposable 
states  of  consciousness;  while  perceptions  are  secondary 
decomposable  states,  consisting  of  changes  from  one  primary 
state  to  another.  Hence,  as  continuance  of  the  primary 
states  is  inconsistent  with  the  occurrence  of  changes,  it  fol- 
lows that  consciousness  of  the  changes  is  in  antagonism  with 
consciousness  of  the  states  between  which  they  occur.  So 
that  perception  and  sensation  are,  as  it  were,  ever  tending 
to  exclude  each  other,  but  never  succeeding.  Indeed, 

consciousness  continues  only  in  virtue  of  this  conflict. 
Without  the  primary  affections  of  consciousness,  there  can 
be  no  changes  from  one  primary  affection  to  another;  and 
without  changes  from  one  to  another,  there  can  be  no 
primary  affections,  since  in  the  absence  of  changes  con- 
sciousness ceases.  Neither  consciousness  of  the  changes, 
nor  of  the  affections  between  which  they  occur,  can  exist  by 
itself.  Nevertheless,  either  may  so  predominate  as  greatly 
to  subordinate  the  other.  When  the  changes  are  so  rapid 
that  the  states  forming  their  antecedents  and  consequents 
do  not  last  for  appreciable  times,  consciousness  is  almost 
wholly  occupied  with  changes — with  the  relations  among 


476  SPECIAL  SYNTHESIS. 

sensations:  sensations  are  present  so  far  only  as  is  needful 
for  the  establishment  of  relations  among  them;  and  we  have 
that  condition  of  consciousness  called  perception.  On  the 
other  hand,  when  the  states  forming  the  antecedents  and 
consequents  of  the  changes  have  considerable  persistence,  or 
rather  when  they  are  not  permanently  destroyed  by  the 
changes  but  continually  return,  and  are  thus  broken  by  the 
changes  only  so  far  as  is  needful  to  maintain  consciousness 
— when,  therefore,  some  one  of  them  by  its  continuous  recur- 
rence, greatly  predominates  over  others;  then  there  results 
the  condition  of  consciousness  called  sensation. 

^ow  this  is  just  the  relationship  which  exists  throughout 
between  knowing  in  general  and  feeling  in  general.  Though 
differing  from  Sir  William  Hamilton  respecting  the  inter- 
pretation of  the  antagonism  between  perception  and  sensa- 
tion, I  agree  with  him  in  holding  that  the  same  antagonism 
holds  between  cognition  and  emotion.  The  differences  are 
simply  differences  that  arise  from  successive  complications. 
As,  out  of  those  simple  perceptions  forming  the  lowest  class 
of  cognitions,  the  higher  cognitions  result  by  the  com- 
pounding of  perceptions;  so,  out  of  those  simple  sensations 
forming  the  lowest  class  of  feelings,  the  higher  feelings  arise 
by  the  compounding  of  sensations.  And  as,  when  cognitions 
grow  highly  compound  their  elements  become  too  nume- 
rous to  be  all  present  together,  and  so  become  partly  repre- 
sentative, and  afterwards  sometimes  wholly  representative; 
so,  when  the  feelings  grow  highly  compound  their  elements 
become  too  numerous  to  be  all  present  together,  and  so 
become  partly  representative,  and  afterwards  sometimes 
wholly  representative.    These  positions  require  elucidation. 

It  has  been  from  time  to  time  pointed  out  that,  in  the 
development  of  Mind,  there  is  a  progressive  consoli- 
dation of  states  of  consciousness.  States  of  consciousness 
once  separate  become  indissociable.  Other  states  that 
were  originally  united  with  difficulty,  grow  so  coherent 
as   to   follow    one   another   without    effort.      And    thus 


THE  FEELINGS.  477 

there  arise  large  aggregations  of  states,  answering  to  com- 
plex external  things — animals,  men,  buildings — which  are 
so  welded  together  as  to  be  practically  single  states.  But 
this  integration,  by  uniting  a  large  number  of  related  sensa- 
tions into  one  state,  does  not  destroy  them.  Though  sub- 
ordinated as  parts  of  a  whole,  they  still  exist.  And  being 
severally  in  their  original  iorias,  J'eeUngs,  this  state  which  is 
composed  of  them  is  a./eding — a  feeling  produced  by  the 
fusing  of  a  number  of  minor  feelings.  Hence  a  certain 
pleasure  accompanying  all  kinds  of  perceptions;  as  every 
child  shows  us.  Not  only,  however,  does  this  hold  with  the 
groups  of  simple  sensations  that  are  united  to  form  percep- 
tions; but  it  holds  with  groups  of  these  groups.  When 
the  composite  states  of  consciousness  answering  to  single 
complex  objects,  become  sufficiently  consolidated;  then,  if 
the  daily  experiences  present  some  constant  assemblage  of 
complex  objects,  such  as  those  distinguishing  a  particular 
locality,  there  results  a  consolidation  of  these  into  a  still 
larger  aggregate  of  states:  the  feelings  severally  consti- 
tuted by  these  composite  states,  are,  in  their  turn,  merged 
into  a  more  composite  feeling,  which  in  its  mixed  and  com- 
paratively massive  character  verges  on  the  emotional.  And 
then  from  the  union  of  this  composite  feeling  with  other 
composite  feelings,  the  elements  of  which  are  mainly  repre- 
sentative, such  as  those  implied  in  the  domestic  relations, 
there  is  produced  an  extremely  involved  and  massive 
feeling  of  the  emotional  order,  answering  to  the  idea, 
home.  But  now  let  it  be  remarked  that  as  fast 

as  these  compound  states  of  consciousness  in  their  ascend- 
ing grades,  severally  become,  by  integration  of  their 
elements,  practically  single;  so  fast  do  they  begin  to  play 
the  same  parts  in  the  mental  processes  that  single  states 
do.  The  continuance  of  a  sensation  being  inconsistent  with 
the  occurrence  of  a  change,  we  saw  that  consciousness  of 
changes,  or  relations  among  sensations,  is  ever  at  variance 
with    consciousness    of    the    sensations.      Here    we    may 


478  SPECIAL  SYNTHESIS. 

similarly  see  that  in  proportion  as  a  composite  feeling  includ- 
ing many  sensations  and  their  relations,  becomes  consoli- 
dated, its  continuance  must  be  at  variance  with  the  occur- 
rence of  a  change  to  some  other  composite  feeling;  that  is — 
must  be  at  variance  with  the  establishment  of  a  relation  be- 
tween the  thing  causing  such  composite  feeling,  and  any- 
thing else;  that  is — must  be  at  variance  with  cognition. 
And  hence  arises  the  fact  known  to  persons  analytically  in- 
clined, that  when  they  think  about  any  gratification  they  are 
receiving — speculate  upon  the  cause  of  it,  or  criticise  the 
object  of  it — the  gratification  is  suspended. 

These  several  expositions  have,  I  think,  made  it  clear 
that  cognition  and  feeling,  throughout  all  phases  of  their 
evolution,  are  at  once  antithetical  and  inseparable.  The 
implication  is  that  they  are  but  diflPerent  aspects  of  the  same 
development,  and  may  so  be  expected  to  arise  from  the 
same  root  by  the  same  process.  This  being  understood  we 
may  now  go  on  to  consider  the  feelings  synthetically. 

§  212.  Where  action  is  perfectly  automatic,  feeling  does 
not  exist.  Of  this  we  have  several  proofs.  We  have  the 
proof  that  in  creatures  most  markedly  exhibiting  them, 
automatic  actions  go  on  equally  well  when  the  cnief  nervous 
centre  has  been  removed.  We  have  the  proof  that  our  own 
automatic  actions  are  unaccompanied  by  feelings:  as  wit- 
ness those  of  the  viscera  in  their  normal  states.  And  we 
have  the  further  proof  that  actions  which  in  ourselves  are 
partly  voluntary,  partly  reflex  (as  that  by  which  the  foot  is 
withdrawn  from  the  scalding  water),  and  which,  so  long  as 
they  are  accompanied  by  feeling,  are  accompanied  by  will, 
become  more  energetically  automatic  if  feeling  is  lost. 
When  injury  of  the  afferent  nerves  has  destroyed  sensibility 
in  a  limb,  the  slightest  stimulus,  as  the  touch  of  a  feather, 
produces  reflex  movements  that  are  stronger  than  those  pro- 
duced in  a  limb  retaining  its  sensibility. 

This  antagonism  of  automatic  action  and  feeling  will  be 


THE  FEELINGS.  479 

better  understood  on  observing  that  feeling  involves  a  per- 
sistence which  automatic  action  negatives.  To  have  the 
state  of  consciousness  recognizable  as  a  particular  feeling, 
implies  some  duration  of  that  state ;  and  in  proportion  as  it 
fills  a  smaller  interval  in  the  chain  of  states,  in  the  same 
proportion  does  it  lapse  out  of  consciousness — in  the  same 
proportion  does  it  cease  to  be  felt.  The  proposition  is  a 
truism.  To  say  that  a  state  of  consciousness  has  consider- 
able continuity,  is  to  say  that  it  is  a  distinct  element  of 
consciousness;  which  is  the  same  thing  as  being  known  or 
felt.  To  say  that  it  has  scarcely  any  continuity,  is  to  say 
that  it  forms  a  scarcely  perceivable  element  in  conscious- 
ness; which  is  the  same  thing  as  being  scarcely  at  all 
known  or  felt.  And  to  say  that  it  is  a  state  of  conscious- 
ness having  no  appreciable  length,  is  to  say  that  it  forms  no 
element  in  consciousness;  which  is  the  same  thing  as  being 
not  known  or  felt.  It  follows,  therefore,  that  when  a  set 
of  psychical  changes  occurs  instantaneously,  the  psychical 
states  forming  the  antecedents  and  consequents  of  the 
changes  are  not  felt;  and  the  further  the  consolidation  of 
any  set  of  psychical  changes  is  carried,  the  more  complete 
must  be  the  absence  of  feeling.  Now  the  completely-con- 
solidated sets  of  changes  are  the  automatic  changes.  The 
automatic  changes  are  those  of  which  the  elements  are 
practically  fused  into  one  change.  Consequently,  where  all 
the  psychical  actions  are  perfectly  automatic,  there  is  no 
feeling. 

Wliile  an  entire  absence  of  Memory  and  Reason  is  accom- 
panied by  an  entire  absence  of  Feeling,  the  same  progress 
which  gives  origin  to  Memory  and  Reason  simultaneously 
gives  origin  to  Feeling.  For  what  did  we  find  to  be  the 
circumstances  under  which  Memory  and  Reason  become 
nascent?  We  found  that  when  the  adjustments  of  the 
organism  to  its  environment  begin  to  take  in  involved  and 
infrequent  groups  of  outer  relations — when,  consequently, 
the  answering  groups  of  inner  relations  include  many  ele- 


480  SPECIAL  SYNTHESIS. 

ments,  of  whicli  some  are  not  often  repeated  in  experience 
— when,  that  is,  there  are  formed  groups  of  inner  relations 
whose  components  are  imperfectly  coherent — when,  as  a 
necessary  result,  there  come  to  be  hesitating  automatic 
actions;  then,  Memory  and  Reason  simultaneously  become 
nascent.  The  ceasing  to  be  automatic  and  the  becoming 
rational,  are,  as  we  saw,  the  same  thing.  We  have  just 
seen,  however,  that  when  psychical  changes  are  perfectly 
automatic,  they  are  without  feeling.  The  existence  of  feel- 
ing we  have  seen  to  imply  psychical  states  having  some  per- 
sistence. But  psychical  states  having  some  persistence  are 
the  states  which  result  when  automatic  action  fails.  Thus 
then,  as  the  psychical  changes  become  too  complicated  to 
be  perfectly  automatic,  they  become  incipiently  sensational. 
Memory,  Reason,  and  Feeling  take  their  rise  at  the  same 
time. 

A  confirmation  of  this  view,  parallel  to  confirmations  given 
in  the  two  preceding  chapters,  may  be  set  down.  Among 
our  own  mental  processes,  many  of  which  were  once  slow,  and 
were  then  accompanied  by  feeling,  are  by  the  same  repeti- 
tion which  renders  them  automatic,  also  rendered  indifferent 
or  f  eelingless.  This  is  equally  the  case  whether  the  accom- 
panying feelings  are  painful  or  pleasurable.  In 
spelling  out  its  reading-lessons,  the  child  experiences  a 
disagreeable  sense  of  effort;  but  in  the  adult,  the  identifi- 
cation of  words  is  a  totally  unemotional  process.  The 
learning  of  a  new  language  requires  labour  that  is  more 
or  less  unpleasant,  and  the  first  attempts  to  speak  it  soon 
produce  weariness;  but  after  due  practice  it  is  spoken  with 
entire  indifference.  And  not  to  multiply  illubtrations,  I 
may  quote  the  general  remark  that  habit  renders  easy  the 
actions  that  once  were  hard,  as  showing  that  this  law 
holds  throughout;  since  by  calling  actions  hxird  we  mean 
to  some  extent  painful,  and  becoming  easy  is  ceasing  to  be 
painful.  Equally  general  is  the  kindred  truth. 
So  long  as  the  combinations  of  properties  they  present  are 


THE  FEELINGS.  481 

new  to  it,  the  commonest  objects  give  pleasure  to  tlie 
infant;  but  as  fast  as,  by  constant  repetition,  the  com- 
pound impressions  produced  become  consolidated  into  per- 
fect cognitions  of  the  objects,  so  fast  do  the  objects  become 
indifferent.  Throughout  childhood,  youth,  and  manhood, 
the  same  fact  is  daily  manifested.  The  often-repeated 
groups  of  psychical  changes  cease  to  be  interesting;  and 
there  arises  a  demand  for  those  that  have  not  been  experi- 
enced, or  have  been  little  experienced. 

The  parallel  is  complete.  We  found  that  not  only  do 
Memory  and  Reason  begin  where  the  psychical  changes 
cease  to  be  automatic;  but  that  where  they  have  existed 
they  disappear  when,  by  perpetual  repetition,  the  psychical 
changes  become  automatic.  And  here  we  find  both  that 
Feeling  arises  under  the  same  conditions,  and  that  it  ceases 
under  the  same  conditions. 

Let  us  now  devote  our  attention  to  the  genesis  of  Feel- 
ings of  more  complex  kinds. 

§  213.  When  there  come  to  be  cases  in  which  two 
very  similar  groups  of  external  attributes  and  relations 
have  been  followed  in  experience  by  different  motor 
changes;  and  when,  consequently,  the  presentation  of  one 
of  these  groups  partially  excites  two  sets  of  motor 
changes,  each  of  which  is  prevented  by  their  mutual  anta- 
gonism from  at  once  taking  place;  then,  while  one  of 
these  sets  of  nascent  motor  changes  and  nascent  im- 
pressions habitually  accompanying  it,  constitutes  a  memory 
oi  such  motor  changes  as  before  performed  and  impressions 
as  before  received,  and  while  it  also  constitutes  Si  prevision 
of  the  action  appropriate  to  the  new  occasion,  it  further  con- 
stitutes the  desire  to  perform  the  action.  For  different  as 
these  three  things  eventually  become,  they  are  originally 
one.  A  further  development  of  an  illustration  already  used 
will  make  this  manifest.  Suppose  the  subject  of 

the  psychical   phenomena   we   are   considering,   to   have 


482  SPECIAL  SYNTHESIS. 

occasional  experiences  of  two  animals  somewhat  similar  in 
colour,  size,  and  general  contour,  one  of  which  serves  for 
prey  and  the  other  of  which  is  a  dangerous  enemy.  The 
complex  impression  produced  by  the  enemy,  has  been  fol- 
lowed in  experience  by  injuries,  by  some  defensive  actions, 
by  certain  cries,  and  eventually  by  flight.  The  complex 
impression  produced  by  the  prey  has  been  followed  in  ex- 
perience by  motions  of  pursuit,  by  successful  grappling  and 
biting,  by  processes  of  tearing  to  pieces  and  swallowing.  But 
as  these  two  complex  impressions  have  many  elements  in 
common,  each  tends  in  so  far  as  there  is  a  confusion  between 
them,  to  arouse  either  of  these  two  sets  of  psychical  changes; 
and  when  one  of  these  similar  animals  is  seen,  each  set  be- 
comes nascent  according  as  the  impression  produced  varies. 
At  one  moment  the  defensive  actions,  the  cries,  and  the 
movements  of  escape,  which  have  followed  some  such  im- 
pression as  that  received,  tend  to  arise;  and  the  next 
moment  a  change  in  the  position  of  the  perceived  animal  so 
alters  the  impression,  as  partially  to  excite  the  psychical 
states  involved  in  pursuit,  attack,  destroying,  and  devouring. 
But  what  is  either  of  these  partial  excitations?  It  is  nothing 
else  than  an  ^notional  impulse — a  combination  of  represen- 
tative feelings  which  forms  the  stimulus  to  action — a  desire 
To  have  in  a  slight  degree  such  psychical  states  as  accom- 
pany the  reception  of  wounds,  and  are  experienced  during 
flight,  is  to  be  in  a  state  of  what  we  call  fear.  And  to  have 
in  a  slight  degree  such  psychical  states  as  the  processes  of 
catching,  killing,  and  eating  imply,  is  to  have  the  desires  to 
catch,  kill,  and  eat.  That  the  propensities  to  the 

acts  are  nothing  else  than  nascent  excitations  of  the 
psychical  state  involved  in  the  acts,  is  proved  by  the  natural 
language  of  the  propensities.  Fear,  when  strong,  expresses 
itself  in  cries,  in  efforts  to  escape,  in  palpitations,  in 
tremblings;  and  these  are  just  the  manifestations  that  go 
along  with  an  actual  suffering  of  the  evil  feared.  The  de- 
structive passion  is  shown  in  a  general  tension  of  the  mus- 


THE  FEELINGS.  483 

cular  system,  in  gnashing  of  teeth  and  protrusion  of  the 
claws,  in  dilated  eyes  and  nostrils,  in  growls ;  and  these  are 
weaker  forms  of  the  actions  that  accompany  the  killing  of 
prey.  To  such  objective  evidences,  every  one  can  add  sub- 
jective evidences.  Every  one  can  testify  that  the  psychical 
state  called  fear,  consists  of  mental  representations  of  certain 
painful  results;  and  that  the  one  called  anger,  consists  of 
mental  representations  of  the  actions  and  impressions  which 
would  occur  while  inflicting  some  kind  of  pain. 

Possibly  it  may  be  objected,  that  to  describe  the  group  of 
nascent  psychical  changes  produced  by  some  complex  im- 
pression, as  constituting  at  once  a  Tnemory  of  the  psychical 
changes  which  had  before  followed  this  impression  and  a 
desire  again  to  go  through  such  changes,  is  absurd;  since 
the  subject-matter  of  memory  is  retrospective,  while  that  of 
desire  is  prospective.  The  reply  is,  that  though,  when  a 
high  degree  of  intelligence  has  been  reached,  these  nascent 
changes  are  joined  with  a  consciousness  of  time  past  and 
time  future,  and  so  come  to  have  different  aspects;  yet,  at 
the  stage  in  which  automatic  action  merges  into  the  higher 
forms  of  action,  no  such  abstract  conception  as  that  of  Time 
can  exist,  and  no  such  duality  of  aspect  in  these  groups  of 
nascent  psychical  changes  can  arise.  And  a  further  reply 
is,  that  even  in  ourselves,  acts  and  feelings  which  become 
nascent  in  connexion  with  the  idea  of  something  prospective, 
are  at  the  same  time  retrospective;  since  they  cannot  be 
represented  at  all  unless  they  have  been  previously  pre- 
sented in  experience,  and  the  representation  of  anything 
previously  presented  is  memory. 

§  214.  The  progress  from  these  forms  of  feeling  consider- 
ably compounded  to  those  highly-compounded  forms  of  feel- 
ing seen  in  human  beings,  equally  harmonizes  with  the 
general  principles  of  evolution  that  have  been  laid  down. 
We  saw  that  advance  from  the  simplest  to  the  most  complex 
cognitions,  is  explicable  on  the  principle  that  the  outer  rela- 


484  SPECIAL  SYNTHESIS. 

tions  produce  the  inner  relations.  We  shall  see  that  this 
same  principle  supplies  an  explanation  of  the  advance  from 
the  simplest  to  the  most  complex  feelings. 

For  when  the  development  of  Life  reaches  this  repeated- 
ly-described stage  in  which  automatic  actions  merge  into  ac- 
tions that  are  at  once  conscious,  rational,  and  emotive;  what 
must  be  the  effect  of  further  experiences?  The  effect  must 
be  that  if,  in  connexion  with  a  group  of  impressions  and  the 
nascent  motor  changes  resulting  from  it,  there  is  habitually 
experienced  some  other  impression  or  group  of  impressions, 
some  other  motor  change  or  group  of  motor  changes,  this 
will,  in  process  of  time,  be  rendered  so  coherent  to  the 
original  group,  that  it,  too,  will  become  nascent  when 
the  original  group  becomes  nascent,  and  will  render  the 
original  group  nascent  if  it  is  itself  induced.  Let  us  take 
a  case.  If  along  with  the  running  down  of 

certain  prey,  a  certain  scent  has  been  habitually  expe- 
rienced, then,  the  presentation  of  that  scent  will  render 
nascent  the  motor  changes  and  impressions  which  accom- 
pany the  running  down  of  the  prey.  If  the  motor  changes 
and  impressions  that  precede  and  accompany  the  catching 
of  prey,  have  been  constantly  followed  by  destructive 
actions,  then,  when  they  are  rendered  nascent,  they  will  in 
their  turn  render  nascent  the  psychical  states  implied  by 
destructive  actions.  And  if  these  have  been  followed  by 
those  connected  with  eating,  then  those  connected  with 
eating  will  also  be  made  nascent.  So  that  the  simple 
olfactory  sensation  will  make  nascent  those  many  and 
varied  states  of  consciousness  involved  in  the  running 
down,  catching,  killing,  and  eating  of  prey:  the  sensa- 
tions, visual,  auditory,  tactual,  gustatory,  muscular,  that 
are  bound  up  with  the  successive  phases  of  these  actions, 
will  be  present  to  consciousness  as  what  we  call  ideas — will, 
in  their  aggregate,  constitute  the  desires  to  catch,  kill,  and 
devour — and  will,  in  conjunction  with  that  olfactory  sensa- 
tion which  aroused  them  all,  form  the  impulse  which  sets 


THE  FEELINGS.  486 

going  tlie  limbs  in  pursuit.  The  entire  genesis  of  these 
emotions  thus  results  from  successive  complications  in  the 
groups  of  psychical  states  that  are  co-ordinated;  and  is 
just  as  much  determined  by  experience  as  is  the  union  of 
any  two  simple  sensations  that  constantly  occur  together. 

A  like  explanation  may  be  given  of  emotions  which  leave 
the  subject  of  them  comparatively  passive;  as,  for  instance, 
that  produced  by  scenery.  By  compounding  groups  of  sensa- 
tions and  ideas  there  are  at  length  formed  those  vast  aggre- 
gations which  a  grand  landscape  excites  and  suggests.  An 
infant  taken  into  the  midst  of  mountains,  is  totally  un- 
affected ;  but  is  delighted  with  the  small  group  of  attributes 
and  relations  presented  in  a  toy.  Children  can  appreciate, 
and  be  pleased  with,  the  more  complicated  relations  of 
household  objects  and  localities — of  the  garden,  the  field, 
and  the  street.  But  it  is  only  in  youth  and  mature  age, 
when  individual  things  and  small  assemblages  of  them  have 
become  familiar  and  are  automatically  cognizable,  that  those 
immense  assemblages  which  landscapes  present  can  be  ade- 
quately grasped,  and  the  highly  integrated  states  of  con- 
sciousness produced  by  them,  experienced.  Then,  however, 
the  various  minor  groups  of  states  that  have  been  in  earlier 
days  severally  produced  by  trees  and  flowers,  by  fields  and 
moors  and  rocky  wastes,  by  streams,  by  cascades,  by  ravines 
and  precipices,  by  blue  skies  and  clouds  and  storms,  are 
aroused  together.  Along  with  the  immediate  sensations 
there  are  partially  excited  the  myriads  of  sensations 
that  have  been  in  times  past  received  from  objects  such 
as  those  presented;  further,  there  are  partially  excited 
the  multitudinous  incidental  feelings  that  were  experienced 
on  these  many  past  occasions;  and  there  are  also  excited 
certain  deeper,  but  now  vague,  combinations  of  states  which 
were  organized  in  the  race  during  barbarous  times,  when  its 
pleasurable  activities  were  chiefly  among  the  woods  and 
waters.  And  out  of  all  these  excitations,  some  of  them 
actual  but  most  of  them  nascent,  is  composed  the  emotion 
which  a  fine  landscape  produces  in  us. 


486  SPECIAL  SYNTHESIS. 

§  215.  One  of  the  corollaries  from  the  foregoing  doctrines 
is  that,  other  things  equal,  feelings  are  strong  in  proportion 
as  they  include  many  actual  sensations,  or  nascent  sensa- 
tions, or  both.  As  every  one  of  the  elementary  states  of 
consciousness  aggregated  in  the  way  described,  is  originally 
a  feeling  of  some  kind;  and  as  progressive  integration 
though  it  abbreviates  each,  leaves  it  to  the  last  a  feeling, 
however  infinitesimal  in  amount;  it  follows  that  the 
greater  the  accumulation  of  such  infinitesimal  amounts  of 
feeling,  the  greater  must  be  the  sum  total  of  feeling  ex- 
perienced. Quantity  of  feeling  is  of  two  kinds — 
that  which  arises  from  intense  excitation  of  few  nerves,  and 
that  which  arises  from  slight  excitation  of  many  nerves. 
Thus,  an  unbearable  sensation  results  if  the  tip  of  a  finger 
be  held  in  boiling  water.  Conversely,  though  there  is  no 
difficulty  in  holding  the  tip  of  a  finger  in  water  above 
110°  Fahrenheit,  an  unbearable  sensation  results  if  the 
whole  body  be  plunged  into  water  of  that  temperature. 
So  that  the  moderate  excitation  of  all  the  nerves  distributed 
over  the  surface  of  the  body,  is  equivalent,  as  measured  by 
its  motor  effects,  to  the  extreme  excitation  of  a  few  of  them. 
Similarly,  though  a  very  faint  colour  cannot  be  discerned 
when  it  covers  only  a  very  minute  surface;  yet,  when  it 
covers  a  great  surface  it  can  be  discerned  with  ease.  And 
that  the  truth  thus  holding  with  actual  sensations,  holds 
also  with  those  nascent  sensations  which,  as  aggregated  into 
masses  of  ideas,  distinct  and  indistinct,  constitute  the  emo- 
tions, will  be  manifest  on  calling  to  mind  how  actions  are 
continually  determined  by  the  accumulation  of  motives; 
that  is,  by  the  accumulation  of  such  nascent  feelings. 

From  this  corollary  there  is  a  second  corollary.  With  a 
qualification  to  be  hereafter  made,  the  higher  the  evolution 
rises  the  stronger  do  the  emotions  become.  For  as  the 
increasingly-complex  emotions  successively  developed,  re- 
sult from  integration  of  pre-existing  groups  of  actual  and 
nascent  sensations,   the  resulting  totals  must  grow  con- 


THE  FEELINGS.  487 

tinually  larger.  A  marked  illustration  of  this 

truth  is  furnished  by  the  passion  which  unites  the 
sexes.  This  is  habitually  spoken  of  as  though  it  were  a 
simple  feeling;  whereas  it  is  the  most  compound,  and 
therefore  the  most  powerful,  of  all  the  feelings.  Added  to 
the  purely  physical  elements  of  it,  are  first  to  be  noticed 
those  highly  complex  impressions  produced  by  personal 
beauty;  around  which  are  aggregated  a  variety  of  plea- 
surable ideas,  not  in  themselves  amatory,  but  which  have 
an  organized  relation  to  the  amatory  feeling.  With  this 
there  is  united  the  complex  sentiment  which  we  term 
affection — a  sentiment  which,  as  it  can  exist  between  those 
of  the  same  sex,  must  be  regarded  as  an  independent  sen- 
timent, but  one  which  is  here  greatly  exalted.  Then  there 
is  the  sentiment  of  admiration,  respect,  or  reverence:  in 
itself  one  of  considerable  power,  and  which  in  this  relation 
becomes  in  a  high  degree  active.  There  comes  next  the 
feeling  called  love  of  approbation.  To  be  preferred  above 
all  the  world,  and  that  by  one  admired  beyond  all  others,  is 
to  have  the  love  of  approbation  gratified  in  a  degree  passing 
every  previous  experience :  especially  as  there  is  added  that 
indirect  gratification  of  it  which  results  from  the  preference 
being  witnessed  by  unconcerned  persons.  Further,  the 
allied  emotion  of  self-esteem  comes  into  play.  To  have 
succeeded  in  gaining  such  attachment  from,  and  sway  over, 
another,  is  a  proof  of  power  which  cannot  fail  agreeably  to 
excite  the  a/mowr  propre.  Yet  again,  the  proprietary  feel- 
ing has  its  share  in  the  general  activity:  there  is  the  plea- 
sure of  possession — the  two  belong  to  each  other.  Once 
more,  the  relation  allows  of  an  extended  liberty  of  action. 
Towards  other  persons  a  restrained  behaviour  is  requisite. 
Round  each  there  is  a  subtle  boundary  that  may  not  be 
crossed — an  individuality  on  which  none  may  trespass.  But 
in  this  case  the  barriers  are  thrown  down;  and  thus  the 
love  of  unrestrained  activity  is  gratified.  Finally,  there  is 
an  exaltation  of  the  sympathies.    Egoistic  pleasures  of  ay 


488  SPECIAL  SYNTHESIS. 

kinds  are  doubled  by  another's  sympathetic  participation; 
and  the  pleasures  of  another  are  added  to  the  egoistic 
pleasures.  Thus,  round  the  physical  feeling  forming  the 
nucleus  of  the  whole,  are  gathered  the  feelings  produced  by 
personal  beauty,  that  constituting  simple  attachment,  those 
of  reverence,  of  love  of  approbation,  of  self-esteem,  of  pro- 
perty, of  love  of  freedom,  of  sympathy.  These,  all  greatly 
exalted,  and  severally  tending  to  reflect  their  excitements 
on  one  another,  unite  to  form  the  mental  state  we  call 
love.  And  as  each  of  them  is  itself  comprehensive  of  mul- 
titudinous states  of  consciousness,  we  may  say  that  this 
passion  fuses  into  one  immense  aggregate  most  of  the  ele- 
mentary excitations  of  which  we  are  capable;  and  that 
hence  results  its  irresistible  power. 

Other  emotions  than  those  which  arise  by  the  simple 
aggregation  of  large  groups  of  psychical  states  into  still 
larger  groups,  are  similarly  interpretable.  There  goes  on 
at  the  same  time,  and  as  a  result  of  the  same  cause,  an  evo- 
lution of  emotions  that  are  not  only  more  complex,  but  also 
more  abstract.  Of  this,  the  love  of  property  supplies  an 
example.  When  the  development  of  intelligence 

has  rendered  time  and  locality  cognizable;  and  when,  by 
consequence,  an  uneaten  portion  of  food  can,  when  hunger 
next  makes  nascent  the  psychical  states  that  accompany 
eating,  be  remembered  as  having  been  left  in  a  particular 
place;  then,  repetition  of  these  experiences  of  a  satiated 
hunger,  and  a  subsequently-recurring  hunger  that  prompts 
return  to  the  remaining  food,  will  establish  an  organized 
connexion  between  the  remembrance  of  such  remaining  food 
and  the  various  states  of  consciousness  produced  by  a  return 
to  it.  Thus  will  be  constituted  an  anticipation  of  a  return 
to  it — a  tendency  to  perform  all  such  actions  accompanying 
a  return  to  it  as  are  not  negatived  by  satiety — a  tendency, 
therefore,  to  take  possession  of  it.  An  analogous  process 
will  develop  a  tendency  to  take  possession  of  some  habitual 
place  of  shelter;  and  afterwards  to  take  possession  of  things 


THE  FEELINGS.  489 

serving  for  artificial  shelter  and  for  clothing.  Later  still, 
things  indirectly  connected  with  personal  welfare  will  come 
to  be  included ;  as,  for  instance,  the  club  used  for  a  weapon, 
the  impressions  produced  by  which  will  make  nascent  the 
various  pleasurable  feelings  that  have  accompanied  its  suc- 
cessful use,  and  the  conception  of  further  use.  The  same 
process  rising  to  still  higher  complications,  will  generate  a 
propensity  to  take  possession  not  only  of  various  weapons 
and  appliances  of  daily  life,  but  also  of  the  tools  and 
materials  required  to  make  such  weapons  and  appliances; 
afterwards  of  the  materials  required  to  make  such  tools;  and 
so  on  until  the  things  accumulated  for  one  purpose  or  other 
become  numerous  and  varied.  But  now  ob- 

serve that  in  proportion  as  these  things  become  numerous 
and  varied,  and  in  proportion  as  the  acts  of  acquiring  them 
and  preserving  them  become  frequent,  a  great  variety  of 
pleasurable  excitements  will  come  to  be  associated  with  the 
act  of  taking  possession  or  holding  possession.  Hence  this 
act  itself,  being  continually  the  initiator  of  pleasurable  ex- 
citements, will  become  a  source  of  pleasurable  excitement. 
And  as  the  excitement  thus  caused  must  be  more  habitual 
than  that  caused  by  any  particular  order  of  objects;  as, 
further,  the  special  excitements  attaching  to  special  objects 
possessed,  must,  in  virtue  of  their  variety,  prevent  the  ex- 
citement of  possession  from  being  connected  with  any  one  of 
them  in  particular;  it  results  that  the  excitement  of  pos- 
session will  grow  into  one  of  a  new  kind,  uniting  into  a 
large  but  vague  aggregate  the  various  excitements  to  which 
it  ministers.  And  when  money  comes  to  be  the  represen- 
tative of  value  in  general — value  as  abstracted  from  special 
objects — the  miser  shows  us  how  the  desire  of  possession  in 
the  abstract  may  become  almost  independent  of  those  from 
which  it  arose;  and  may  exceed  in  strength  any  of  them  in- 
dividually. 

As  further  illustrating  the  origin  and  nature  of  the  more 
abstract  emotions,  let  me  add  one  still  in  course  of  evolution 


490  SPECIAL  SYNTHESIS. 

among  civilized  men;  and  as  yet  but  imperfectly  developed. 
I  refer  to  the  desire  for  liberty — the  sentiment  of  personal 
rights.  A  relation  l)ke  that  which  the  love  of  property  bears 
to  the  gratifications  which  property  brings,  this  love  of  un- 
restricted action  bears  to  the  gratifications  derivable  from 
property  and  from  all  other  things.  As  the  satisfaction  of 
the  one  is  in  securing  the  material  objects  directly  or  in- 
directly ministering  to  life;  so  the  satisfaction  of  the  other 
is  in  securing  those  non-7naterial  conditions  without  which 
the  material  objects  can  neither  be  obtained,  nor  preserved, 
nor  used.  While  the  possession  of  certain  kinds  and  com- 
binations of  raatter  is  a  very  general  pre-requisite  to  the  ful- 
filment of  the  desires;  a  still  more  general,  and  indeed  uni- 
versal, pre-requisite  is  that  freedom  of  motion  without  which 
it  is  not  only  impossible  to  get  and  utilize  such  matter,  but 
is  impossible  to  perform  any  action  whatever.  This  senti- 
ment of  personal  rights,  answering  to  certain  complex  rela- 
tions in  which  the  members  of  a  society  stand  to  one  another 
— being  a  gratification  in  the  maintenance  of  such  relations 
with  other  men  as  involve  the  least  restraint  on  individual 
action — is  manifestly  far  more  abstract,  and  far  wider  in  its 
co-ordinations,  than  any  other.  As  uniting  in  one  general 
sentiment  the  desire  for  liberty  of  person,  liberty  of  acqui- 
sition and  possession,  liberty  of  movement  from  place  to 
place,  liberty  of  speech,  liberty  of  trade,  and  so  on,  it  sup- 
poses an  extremely  extensive  aggregation  of  psychical  states. 
It  could  not  begin  to  be  organized  until  mankind  grew  into 
permanent  social  relations,  and  it  has  manifestly  long  been 
in  process  of  development. 

It  remains  to  add  the  qualification  which,  as  above  said, 
must  be  made  to  the  assertion  that  these  central  feelings  or 
emotions  grow  in  power  as  they  grow  in  complexity  and  in 
extent  of  integration.  For  though,  other  things  equal,  the 
power  of  an  emotion  thus  compounded  out  of  clusters  of  ele- 
mentary feelings  ideally  revived,  is  proportionate  to  the 
number  of  such  elementary  feelings  united  in  it;  yet,  very 


THE  PEELINGS.  491 

often  other  things  are  not  equal.  Along  with  greatness  of 
number  there  may  be  lowness  of  intensity.  Where,  as  in 
the  above  case,  the  connexions  established  in  experience  are 
extremely  intricate,  comparatively  infrequent,  and  very 
varied,  the  co-ordination  of  the  states  of  consciousness  is 
so  weak  that  they  render  one  another  nascent  in  but  a  feeble 
way;  and  hence,  the  total  effect  is  in  many  cases  less  than 
that  produced  by  a  smaller  aggregate  more  strongly  ex- 
cited. 

§  216.  After  what  was  said  at  the  close  of  the  last  chapter, 
I  need  hardly  say  that  this  evolution  of  composite  feelings 
through  the  progressive  integration  of  psychical  states  that 
are  connected  in  experience,  is  effected  by  the  inheritance  of 
continually-accumulating  modifications. 

The  law  of  development  of  the  mental  activities  consid- 
ered under  their  cognitive  aspect,  equally  applies  to  them 
considered  under  their  emotional  aspect.  That  gradual  or- 
ganization of  forms  of  thought  which  we  saw  results  from 
the  experience  of  uniform  external  relations,  is  accompanied 
by  the  organization  of  forms  of  feeling  similarly  resulting. 
Given  a  race  of  organisms  habitually  placed  in  contact  with 
any  complex  set  of  circumstances,  and  if  its  members  are 
already  able  to  co-ordinate  the  impressions  made  by  each  of 
the  various  minor  groups  of  phenomena  composing  this  set 
of  circumstances,  there  will  slowly  be  established  in  them  a 
co-ordination  of  these  compound  impressions  corresponding 
to  this  set  of  circumstances.  The  constant  experiences  of 
successive  generations  will  gradually  strengthen  the  ten- 
dency of  all  the  component  clusters  of  psychical  states  to 
make  one  another  nascent.  And  when  ultimately  the  union 
of  them,  expressed  in  the  inherited  organic  structure,  be- 
comes innate,  it  will  constitute  what  we  call  an  emotion  or 
sentiment,  having  this  set  of  circumstances  for  its  object. 

In  their  more  involved  phases  these  compound  forms  of 
feeling  differ  from  the  compound  forms  of  thought  partly 


492  SPECIAL  SYNTHESIS. 

in  tliis,  that  the  assemblages  of  external  attributes  and 
actions  and  relations  to  which  they  answer,  are  immensely 
more  extensive,  far  more  concrete,  and  extremely  miscel- 
laneous and  variable  in  their  ultimate  components.  One 
consequence  of  this  is  that  they  never  lose  their  em- 
pirical character.  A  further  difference  similarly 
implied,  is  that  in  each  form  of  feeling  thus  compounded, 
answering  as  it  does  to  successive  sets  of  external  circum- 
stances which  have  only  a  general  resemblance,  the  rela- 
tional elements  are  never  twice  alike,  and  therefore  cannot 
become  distinctly  fixed;  whence  it  follows  that  the  cogni- 
tive character  of  the  aggregated  states  remaining  feeble, 
their  sentient  character  remains  strong.  A  third 
differential  trait  of  these  central  feelings  must  be  added. 
As  the  clusters  of  elementary  feelings  out  of  which  they  are 
formed,  do  not  recur  in  exactly  the  same  combinations — are 
not,  as  it  were,  super-posed  so  that  their  components  fit  with 
the  like  previous  components;  it  necessarily  happens  that 
the  successive  clusters  blur  one  another,  and  the  com- 
pound feeling  produced  becomes,  though  massive,  very  dim 
or  vague.  An  illustration  will  make  this  effect  compre- 
hensible. Imagine  that  representations  of  many  different 
sunsets,  painted,  let  us  say,  on  glass,  were  placed  over  one 
another,  and  looked  at  by  transmitted  light — what  would  be 
the  result?  Disagreeing  in  the  outlines  of  their  horizons, 
their  clouds,  their  special  objects,  these  super-posed  repre- 
sentations would  make  a  confused  and  hazy  combination,  in 
which  no  particular  thing  and  no  defined  portion  of  colour 
would  be  visible;  but  in  which,  nevertheless,  there  would 
be  these  general  characters — a  glow  in  the  middle  region,  a 
duller  region  above  it,  and  a  comparatively  dark  region 
below.  Similarly,  as  the  successive  impressions  produced 
on  an  individual,  and  a  series  of  individuals,  by  manifesta- 
tions of  anger  in  those  they  come  in  contact  with,  have 
general  but  not  special  resemblances — as  the  harsh  tones, 
the  contorted  features,  and  the  pains  that  are  apt  to  be 


THE  FEELINGS.  493 

suffered  from  the  acts  which  follow,  always  differ  in  their 
details  though  they  have  a  family  likeness;  it  results  that 
the  general  impression  left  unobliterated  by  the  disagreeing 
details  must  be  very  indefinite:  the  gradually-organized 
compound  feeling  which  we  call  fear,  will  have  a  character 
nothing  like  so  specific  as  that  of  a  simple  peripheral  feeling. 

Such  being  the  differences  that  naturally  arise  between 
the  organized  forms  of  feeling  and  the  organized  forms  or 
thought  in  the  course  of  their  evolution,  let  us  now  observe 
the  likenesses  that  naturally  arise. 

As  the  forms  of  thought,  or  the  accumulated  and  trans- 
mitted modifications  of  structure  produced  by  experience,  lie 
latent  in  each  newly-born  individual,  are  vaguely  disclosed 
along  with  the  first  individual  experiences,  and  are  gradually 
made  definite  by  multiplication  of  such  individual  experi- 
ences; so  the  forms  of  feeling  likewise  lying  latent,  are 
feebly  awakened  by  the  first  presentations  of  the  external 
circumstances  to  which  they  refer,  and  gradually  gain  that 
degree  of  distinctness  which  they  are  capable  of,  through 
often-repeated  presentations  of  these  circumstances.  Thus 
the  infant,  as  soon  as  its  perceptions  are  developed  enough 
to  allow  of  even  an  imperfect  discrimination  of  faces  and  of 
sounds,  is  made  to  smile  automatically  by  the  laughing  face 
and  tender  tones  of  its  mother  or  its  nurse.  An  organized 
relation  has  been  established  in  the  race  between  the  percep- 
tion of  this  natural  language  of  kind  feeling  and  the  subse- 
quent experience  of  benefits  from  those  who  manifest  it. 
This  natural  language  being  impressed  on  the  infant's  senses, 
a  dim  feeling  of  pleasure  is  awakened  while  it  is  still  incap- 
able of  knowing  what  the  natural  language  means.  But  in 
course  of  time  personal  experiences  teach  it  the  connexion 
that  exists  between  these  appearances  assumed  by  other 
persons  and  the  receipt  of  gratifications  from  them;  and 
then  the  vague  body  of  the  emotion  which  it  has  inherited 
assumes  a  more  intelligible  form. 

That  the  experience-hypothesis  as  ordinarily  understood, 


494  SPECIAL  SYNTHESIS. 

is  inadequate  to  account  for  emotional  phenomena,  will  be 
sufficiently  manifest.  If  possible,  it  is  even  more  at  fault  in 
respect  to  the  emotions  than  in  respect  to  the  cognitions. 
The  doctrine  that  all  the  desires,  all  the  sentiments,  are 
generated  by  the  experiences  of  the  individual,  is  so  glar- 
ingly at  variance  with  facts,  that  I  cannot  but  wonder  how 
any  one  should  ever  have  entertained  it.  Not  to  dwell  on 
the  multiform  passions  displayed  by  the  infant  before  there 
has  been  such  an  amount  of  experience  as  could  possibly 
suffice  for  the  elaboration  of  them,  I  will  simply  point  to 
the  most  powerful  of  passions — the  amatory  passion — as  one 
which,  when  it  first  occurs,  is  absolutely  antecedent  to  all  re- 
lative experience  whatever. 


CHAPTEK  IX. 


THE    WILL. 


§  217.  All  who  have  followed  the  argument  thus  far, 
will  see  that  the  development  of  what  we  call  Will,  is  but 
another  aspect  of  the  general  process  whose  other  aspects 
have  been  delineated  in  the  last  three  chapters.  Memory, 
Reason,  and  Feeling,  simultaneously  arise  as  the  automatic 
actions  become  complex,  infrequent,  and  hesitating;  and 
Will,  arising  at  the  same  time,  is  necessitated  by  the 
same  conditions.  As  the  advance  from  the  simple  and 
indissolubly-coherent  psychical  changes,  to  the  psychical 
changes  that  are  involved  and  dissolubly  coherent,  is 
in  itself  the  commencement  of  Memory,  Reason,  and 
Feeling;  so,  too,  is  it  in  itself  the  commencement  of 
Will.  On  passing  from  compound  reflex  actions  to  those 
actions  so  highly  compounded  as  to  be  imperfectly  reflex 
— on  passing  from  the  organically-determined  psychical 
changes  which  take  place  with  extreme  rapidity,  to  the 
psychical  changes  which,  not  being  organically  determined, 
take  place  with  some  deliberation,  and  therefore  con- 
sciously; we  pass  to  a  kind  of  mental  action  which  is  one 
of  Memory,  Reason,  Feeling,  or  Will,  according  to  the  side 
of  it  we  look  at. 

Of  this  we  may  be  certain,  even  in  anticipation  of  any 

special  synthesis.    For  since  all  modes  of  consciousness  can 

be  nothing  else  than  incidents  of  the  correspondence  be- 

495 


496  SPECIAL  SYNTHESIS. 

tween  the  organism  and  its  environment;  they  must  all  be 
different  sides  of,  or  different  phases  of,  the  co-ordinated 
groups  of  changes  whereby  internal  relations  are  adjusted  to 
external  relations.  Between  the  reception  of  certain  impres- 
sions and  the  performance  of  certain  appropriate  motions, 
there  is  some  inner  connexion.  If  the  inner  connexion  is 
organized,  the  action  is  of  the  reflex  order,  either  simple  or 
compound;  and  none  of  the  phenomena  of  consciousness 
proper,  exist.  If  the  inner  connexion  is  not  organized,  then 
the  psychical  changes  which  come  between  the  impressions 
and  motions  are  conscious  ones:  the  entire  action  must 
have  all  the  essential  elements  of  a  conscious  action — must 
simultaneously  exhibit  Memory,  Reason,  Feeling,  and  Will; 
for  there  can  be  no  conscious  adjustment  of  an  inner  to  an 
outer  relation  without  all  these  being  involved.  Let  us  con- 
sider the  matter  more  nearly. 

§  218.  When  the  automatic  actions  become  so  involved, 
so  varied  in  kind,  and  severally  so  infrequent,  as  no  longer 
to  be  performed  with  unhesitating  precision — when,  after 
the  reception  of  one  of  the  more  complex  impressions,  the 
appropriate  motor  changes  become  nascent,  but  are  pre- 
vented from  passing  into  immediate  action  by  the  antago- 
nism of  certain  other  nascent  motor  changes  appropriate  to 
some  nearly  allied  impression;  there  is  constituted  a  state 
of  consciousness  which,  when  it  finally  issues  in  action, 
displays  what  we  term  volition.  Each  set  of  nascent  motor 
changes  arising  in  the  course  of  this  conflict,  is  a  weak  re- 
vival of  the  state  of  consciousness  which  accompanies  such 
motor  changes  when  actually  performed — is  a  representa- 
tion of  such  motor  changes  as  were  before  executed  under 
like  circumstances — is  an  idea  of  such  motor  changes.  We 
have,  therefore,  a  conflict  between  two  sets  of  ideal  motor 
changes  which  severally  tend  to  become  real,  and  one  of 
which  eventually  does  become  real;  and  this  passing  of 
an  ideal  motor  change  into  a  real  one,  we  distinguish  as 


THE  WILL.  497 

Will.  In  a  voluntary  act  of  the  simplest  kind,  we 

can  find  nothing  beyond  a  mental  representation  of  the  act, 
followed  by  a  performance  of  it — a  rising  of  that  incipient 
psychical  change  which  constitutes  at  once  the  tendency  to 
act  and  the  idea  of  the  act,  into  the  complete  psychical 
change  which  constitutes  the  performance  of  the  act,  in  so 
far  as  it  is  mental.  Between  an  involuntary  movement  of 
the  leg  and  a  voluntary  one,  the  difference  is  that  whereas 
the  involuntary  one  occurs  without  previous  consciousness 
of  the  movement  to  be  made,  the  voluntary  one  occurs  only 
after  it  has  been  represented  in  consciousness;  and  as  the 
representation  of  it  is  nothing  else  than  a  weak  form  of  the 
psychical  state  accompanying  the  movement,  it  is  nothing 
else  than  a  nascent  excitation  of  the  nerves  concerned,  pre- 
ceding their  actual  excitation.  Involuntary  movement  im- 
plies that  the  psychical  states  accompanying  the  impression 
and  the  action,  are  so  coherent  that  the  one  follows  the 
other  instantly;  while  voluntary  movement  implies  that 
they  are  so  imperfectly  coherent,  that  the  psychical  state 
accompanying  the  action  does  not  follow  instantly — is  par- 
tially aroused  before  it  is  fully  aroused;  and  so  occupies 
consciousness  for  an  appreciable  time.  Thus  the  cessation 
of  automatic  action  and  the  dawn  of  volition  are  one  and 
the  same  thing. 

It  is  quite  true  that  as  we  advance  from  the  earliest  and 
simplest  manifestations  of  Will  to  its  later  and  more  in- 
volved manifestations,  the  composite  state  of  consciousness 
by  which  any  act  is  preceded  includes  much  beyond  the 
nascent  motor  changes,  and  even  much  beyond  the  ideal 
sensory  impressions  which  the  act  will  immediately  render 
real  ones.  It  further  includes  an  extensive  aggregate  of 
ideal  sensory  impressions  such  as  have  before  been  more  or 
less  remotely  realized  by  the  act;  and  which  constitute 
representations  of  the  various  consequences  of  the  act. 
Even  when  Will  is  but  incipient,  there  must  be  some 
accompaniment  of  this  kind.      Along  with  any  two  con- 


498  SPECIAL  SYNTHESIS. 

flicting  sets  of  motor  changes  produced  by  an  indistinctly 
cognized  impression,  there  will  become  nascent  the  several 
pleasurable  or  painful  psychical  states  which  have  in  expe- 
rience been  respectively  connected  with  such  motor  changes. 
These  are  partially  integrated  with  the  other  psychical 
states,  actual  and  nascent,  which  the  impression  immedi- 
ately or  mediately  excites;  and  by  increasing  the  group  of 
psychical  states  which  cohere  with  the  appropriate  motor 
changes,  they  add  to  the  tendency  which  those  motor 
changes  have  to  take  place.  By  that  ever-progressing 
fusion  of  psychical  states  described  in  the  last  chapter, 
these  ideal  sensory  impressions  representing  distant  conse- 
quences, come  to  form  the  greater  part  of  the  composite 
psychical  state  which  precedes  the  act — constitute  the  mass 
of  what  we  call  the  desire  to  perform  the  act;  and  thus 
obscure  that  original  relation  between  sensations  and  mo- 
tions which  is  their  nucleus.  But  the  general  nature  of 
the  process  remains  the*  same.  Feelings,  inunediately  de- 
rived from  the  senses  or  mediately  suggested  by  such,  make 
nascent  certain  appropriate  motor  changes,  and  the  ideal 
feelings  connected  with  such  changes;  these,  again,  make 
nascent  other  changes  and  other  ideal  feelings;  and  so  on 
to  many  degrees  of  remoteness:  producing  a  complicated 
group  of  imagined  actions  and  consequences.  All  of  these 
having,  directly  or  indirectly,  connexions  in  experience 
with  the  motor  changes,  or  with  antagonist  motor  changes, 
tend  to  produce  or  to  prevent  the  action.  An  immense 
number  of  psychical  states  are  partially  aroused,  some  of 
which  unite  with  the  original  impression  in  exciting  the 
action,  while  the  rest  combine  as  exciters  of  an  opposite 
action;  and  when  eventually,  from  their  greater  number  or 
intensity,  the  first  outbalance  the  others,  the  interpretation 
is  that,  as  an  accumulated  stimulus,  they  become  sufficiently 
strong  to  make  the  nascent  motor  changes  pass  into  actual 
motor  changes. 

That  Will  comes  into  existence  through  the  increasing 


THE  WILL.  499 

complexity  and  imperfect  coherence  of  automatic  actions,  is 
clearly  implied  by  the  converse  fact,  that  when  actions 
which  were  once  incoherent  and  voluntary  are  very  fre- 
quently repeated,  they  become  coherent  and  involuntary. 
Just  as  any  set  of  psychical  changes  originally  displaying 
Memory,  Reason,  and  Feeling,  cease  to  be  conscious,  ra- 
tional, and  emotional,  as  fast  as  by  repetition  they  grow 
closely  organized ;  so  do  they  at  the  same  time  pass  beyond 
the  sphere  of  volition.  Memory,  Reason,  Feeling,  and  Will,, 
simultaneously  disappear  in  proportion  as  psychical  changes; 
become  automatic.  Thus,  the  child  learning  to» 

walk,  wills  each  movement  before  making  it;  but  the  admlt^ 
when  setting  out  anywhere,  does  not  think  of  his  legs,  but 
of  his  destination,  and  his  successive  steps  are  made  with 
no  more  volition  than  his  successive  inspirations.  Every 
one  of  those  vocal  imitations  made  by  the  child  in  acqiuiring: 
its  mother  tongue,  or  by  the  man  in  learning  a  new  laBguage^. 
is  voluntarily  made;  but  after  years  of  practice,  eeaiversa- 
tion  is  carried  on  without  thought  of  the  muscular  adjust- 
ments required  to  produce  each  articulation:  th«  motiona 
of  the  larynx  and  mouth  respond  automatically  iQ>  the  trains 
of  ideas.  Similarly  with  writing,  and  all  other  familiar 
processes.  Not  only  is  this  so  with  actions  daily 

occurring  in  the  lives  of  all,  but  it  is  so  with  special  habitsk 
From  time  to  time  curious  results  hence  arise;  as  in  the- 
case  of  the  old  soldier  who  let  fall  the  pie  he  was  carrying: 
home  for  his  Sunday's  dinner,  when  the  word  "  attention  '* 
was  shouted  behind  him.  The  same  general  truth  is  re- 
cognized in  the  common  remark,  made  of  any  one  who  has. 
long  persisted  in  some  evil  practice,  that  "  he  has  lost  power 
over  himself  " — "  can  no  longer  control  himself:  "  that  is  to- 
say,  by  frequent  repetition  certain  psychical  changes  have 
more  or  less  passed  from  the  voluntary  into  the  aurtomatic.*^ 

•  Dr,  Hughlinecs  Jackson  narrates  of  an  animal  an  action  anaTogous  to 
that  of  the  old  soldier.    "  Some  years  ago,"  he  says,.  *•  I  was  on  an  omnibus,. 
83 


500  SPECIAL  SYNTHESIS. 

§  219.  Long  before  reaching  this  point,  most  readers 
must  have  perceived  that  the  doctrines  developed  in  the 
last  two  parts  of  this  work  are  at  variance  with  the  current 
tenets  respecting  the  freedom  of  the  Will.  That  every  one 
is  at  liberty  to  do  what  he  desires  to  do  (supposing  there 
are  no  external  hindrances),  all  admit;  though  people  of 
confused  ideas  commonly  suppose  this  to  be  the  thing 
denied.  But  that  every  one  is  at  liberty  to  desire  or  not 
to  desire,  which  is  the  real  proposition  involved  in  the 
dogma  of  free  will,  is  negatived  as  much  by  the  analysis 
of  consciousness  as  by  the  contents  of  the  preceding  chapters. 
From  the  universal  law  that,  other  things  equal,  the  cohesion 
of  psychical  states  is  proportionate  to  the  frequency  with 
which  they  have  followed  one  another  in  experience,  it  is 
an  inevitable  corollary  that  all  actions  whatever  must  be 
determined  by  those  psychical  connexions  which  experience 
has  generated — either  in  the  life  of  the  individual,  or  in 
that  general  antecedent  life  of  which  the  accumulated  re- 
sults are  organized  in  his  constitution. 

To  go  at  length  into  this  long-standing  controversy  re- 
specting the  Will,  would  be  alike  useless  and  out  of  place. 
I  can  but  briefly  indicate  what  seems  to  me  the  nature  of 
the  current  illusion,  as  interpreted  from  the  point  of  view 
at  which  we  have  arrived.  We  will  look  at  it  first  subjec- 
tively and  then  objectively. 

Considered  as  an  internal  perception,  the  illusion 
results  from  supposing  that  at  each  moment  the  ego^ 
present  as  such  in  consciousness  (I  exclude  the  implied,  but 
unknown,   substratum  which   can   never  be   present),    is 

and  we  were  kept  some  time,  as  one  of  the  horses  would  not  start.  Various 
plans  were  tried  to  overcome  its  stupidity,  but  without  success.  At  last 
the  driver  directed  the  conductor  to  shut  the  door  violently  (this  is  a  usual 
signal  for  starting).  To  my  great  surprise  the  horse  went  on  at  once." 
Lond.  Hosp.  Reports.  Vol.  I.,  1864,  p.  454.  Here  the  once  voluntary  act 
of  starting  after  hearing  the  sound,  had  become  so  automatic  that  an 
antagonist  volition  could  not  prevent  it. 


THE  WILL.  501 

something  more  tlian  the  aggregate  of  feelings  and 
ideas  which  then  exists.  When,  after  a  certain  compo- 
site mass  of  emotion  and  thought  has  arisen  in  him,  a 
man  performs  an  action,  he  commonly  asserts  that  he  deter- 
mined to  perform  the  action;  and  by  speaking  as  though 
there  were  a  mental  self,  present  to  his  consciousness,  yet  not 
included  in  this  composite  mass  of  emotion  and  thought,  he 
is  led  into  the  error  of  supposing  that  it  was  not  this 
composite  mass  of  emotion  and  thought  which  determined 
the  action.  But  while  it  is  true  that  he  determined  the 
action,  it  is  also  true  that  the  aggregate  of  his  feelings 
and  ideas  determined  it;  since,  during  its  existence,  this 
aggregate  constituted  his  entire  consciousness — that  is, 
constituted  his  mental  self.  Either  the  ego  which 

is  supposed  to  determine  or  will  the  action,  is  present  in 
consciousness  or  it  is  not.  If  it  is  not  present  in  con- 
sciousness, it  is  something  of  which  we  are  unconscious — 
something,  therefore,  of  whose  existence  we  neither  have 
nor  can  have  any  evidence.  If  it  is  present  in  conscious- 
ness, then,  as  it  is  ever  present,  it  can  be  at  each  moment 
nothing  else  than  the  total  consciousness,  simple  or  com- 
pound, passing  at  that  moment.  It  follows,  inevitably, 
that  when  an  impression  received  from  without,  makes  nas- 
cent certain  appropriate  motor  changes,  and  various  of  the 
feelings  and  ideas  which  must  accompany  and  succeed 
them;  and  when,  under  the  stimulus  of  this  composite 
psychical  state,  the  nascent  motor  changes  pass  in  actual 
motor  changes;  this  composite  psychical  state  which  excites 
the  action,  is  at  the  same  time  the  ego  which  is  said  to  will 
the  action.  Naturally  enough,  then,  the  subject  of  such 
psychical  changes  says  that  he  wills  the  action;  since, 
psychically  considered,  he  is  at  that  moment  nothing  more 
than  the  composite  state  of  consciousness  by  which  the 
action  is  excited.  But  to  say  that  the  performance  of  the 
action  is,  therefore,  the  result  of  his  free  will,  is  to  say  that 
he  determines  the  cohesions  of  the  psychical  states  which 


502  SPECIAL  SYNTHESIS. 

arouse  the  action;  and  as  these  psychical  states  con- 
stitute himself  at  that  moment,  this  is  to  say  that  these 
psychical  states  determine  their  own  cohesions,  which  is 
absurd.  Their  cohesions  have  been  determined  by  expe- 
riences— the  greater  part  of  them,  constituting  what  we 
call  his  natural  character,  by  the  experiences  of  antecedent 
organisms;  and  the  rest  by  his  own  experiences.  The 
changes  which  at  each  moment  take  place  in  his  conscious- 
ness, and  among  others  those  which  he  is  said  to  will,  are 
produced  by  this  infinitude  of  previous  experiences  regis- 
tered in  his  nervous  structure,  co-operating  with  the  imme- 
diate impressions  on  his  senses :  the  effects  of  these  combined 
factors  being  in  every  case  qualified  by  the  physical  state, 
general  or  local,  of  his  organism. 

This  subjective  illusion  in  which  the  notion  of  free  will 
commonly  originates,  is  strengthened  by  a  corresponding 
objective  illusion.  The  actions  of  other  individuals,  lacking 
as  they  do  that  uniformity  characterizing  phenomena  of 
which  the  laws  are  known,  appear  to  be  lawless — appear  to 
be  under  no  necessity  of  following  any  particular  order; 
and  are  hence  supposed  to  be  determined  by  the  unknown 
independent  something  called  the  Will.  But  this  seeming 
indeterminateness  in  the  mental  succession  is  consequent 
on  the  extreme  complication  of  the  forces  in  action.  The 
composition  of  causes  is  so  intricate,  and  from  moment  to 
moment  so  varied,  that  the  effects  are  not  calculable. 
These  effects  are,  however,  as  conformable  to  law  as  the 
simplest  reflex  actions.  The  irregularity  and  apparent 
freedom  are  inevitable  results  of  the  complexity;  and 
equally  arise  in  the  inorganic  world  under  parallel  con- 
ditions. To  amplify  an  illustration  before  used: — A  body 
in  space,  subject  to  the  attraction  of  a  single  other  body, 
moves  in  a  direction  that  can  be  accurately  predicted.  If 
subject  to  the  attractions  of  two  bodies,  its  course  is  but 
approximately  calculable.  If  subject  to  the  attractions  of 
three  bodies,  its  course  can  be  calculated  with  still  less  pre- 


THE  WILL.  603 

cision.  And  if  on  all  sides  of  it  there  are  multitudinous 
bodies  of  various  sizes  at  various  distances,  as  in  the  middle 
of  one  of  the  great  star-clusters,  its  motion  will  appear  un- 
influenced by  any  of  them :  it  will  move  in  some  indefinable 
way  that  looks  self-determined:  it  will  seem  to  be  free. 
Similarly,  in  proportion  as  the  cohesions  of  each  psychical 
state  to  others,  become  great  in  number  and  various  in 
degree,  the  psychical  changes  will  become  incalculable  and 
apparently  subject  to  no  law. 

§  220.  To  meet  objections  that  have  been  raised,  let  me 
add  here  some  explanations. 

If  we  spoke  of  Henry  VIII.  as  defying  the  Pope,  and 
then  said  that  the  English  King  also  defied  the  Pope, 
there  would  be  a  manifest  mistaking  of  words  for 
things.  The  kingly  power  we  know  to  be  nothing  but 
the  permanent  name  for  the  power  of  a  person,  who 
is  now  of  one  nature  and  now  of  another.  But  in  the 
case  of  mental  government,  this  confusion  between  words 
and  things  is  almost  universal.  The  permanent  name 
for  the  holder  of  power,  is  supposed  to  imply  an  entity 
additional  to  that  implied  by  the  name  of  the  temporary 
holder  of  power.  We  speak  of  Will  as  something  apart 
from  the  feeling  or  feelings  which,  for  a  moment,  prevail 
over  others;  whereas  it  is  nothing  but  the  general  name 
given  to  the  special  feeling  that  gains  supremacy  and 
determines  action.  Take  away  all  sensations  and  emotions, 
and  there  remains  no  Will.  Excite  some  of  these,  and 
Will,  becoming  possible,  becomes  actual  only  when  one 
of  them,  or  a  group  of  them,  gains  predominance.  Until 
there  is  a  motive  (mark  the  word)  there  is  no  Will.  That 
is  to  say.  Will  is  no  more  an  existence  separate  from  the 
predominant  feeling,  than  a  king  is  an  existence  separate 
from  the  man  occupying  the  throne. 

That  the  ego  is  something  more  than  the  passing  group 
of  feelings  and  ideas,  is  true  or  untrue  according  to  the 


504  SPECIAL  SYNTHESIS. 

degree  of  comprehension  we  give  to  the  word.  It  is  true 
if  we  include  the  body,  and  its  functions;  but  it  is  untrue 
if  we  include  only  what  is  given  in  consciousness. 

Physically  considered,  the  ego  is  the  entire  organism, 
including  its  nervous  system;  and  the  nature  of  this  ego  is 
pre-determined:  the  infant  had  no  more  to  do  with  the 
structure  of  its  brain  than  with  the  colour  of  its  eyes. 
Further,  the  ego  considered  physically,  includes  all  the 
functions  carried  on  by  these  structures,  when  supplied  with 
the  requisite  materials.  These  functions  have  for  their 
net  result  to  liberate  from  the  food,  &c.,  certain  latent 
forces.  And  that  distribution  of  these  forces  shown  by  the 
activities  of  the  organism,  is  from  moment  to  moment 
caused  partly  by  the  existing  arrangement  of  its  parts  and 
partly  by  the  environing  conditions. 

The  physical  structures  thus  pervaded  by  the  forces  thus 
obtained,  constitute  that  substantial  ego  which  lies  behind 
and  determines  those  ever-changing  states  of  consciousness 
we  call  Mind.  And  while  this  substantial  ego,  unknowable 
in  ultimate  nature,  is  phenomenally  known  to  us  under  its 
statical  form  as  the  organism,  it  is  phenomenally  known 
under  its  dynamical  form  as  the  energy  diffusing  itself 
through  the  organism,  and,  among  other  parts,  through  the 
nervous  system.  Given  the  external  stimuli,  and  the 
nervous  changes  with  their  correlative  mental  states, 
depend  partly  on  the  nervous  structures  and  partly  on  the 
amount  of  this  diffused  energy:  each  of  which  factors  is 
determined  by  causes  not  in  consciousness  but  beneath  con- 
sciousness. The  aggregate  of  feelings  and  ideas  constitut- 
ing the  mental  /,  have  not  in  themselves  the  principle  of 
cohesion  holding  them  together  as  a  whole;  but  the  1 
which  continuously  survives  as  the  subject  of  these  chang- 
ing states,  is  that  portion  of  the  Unknowable  Power  which 
is  statically  conditioned  in  special  nervous  structures 
pervaded  by  a  dynamically-conditioned  portion  of  the  Un- 
knowable Power  called  energy.    (Compare  with  §  469.) 


PART  Y. 


PHYSICAL   SYNTHESIS. 


CHAPTER  I. 

A   FUETHEB   INTEEPEETATION    NEEDED. 

§  221.  We  are  now  prepared  for  dealing  with  the  remain- 
ing problem  presented  by  objective  Psychology.  Though 
not  conspicuous,  the  hiatus  between  the  interpretation  we 
have  reached  and  a  complete  interpretation,  is  a  deep  one; 
and  one  which,  when  first  looked  into,  appears  impassable. 
For  there  has  still  to  be  answered  the  inquiry — how  is  mental 
evolution  to  be  affiliated  on  Evolution  at  large,  regarded  as 
a  process  of  physical  transformation?  It  is  not  enough  that 
in  the  preceding  General  Synthesis  the  phenomena  of  psy- 
chical life  have  been  traced  up  through  their  objective 
manifestations,  and,  along  with  the  phenomena  of  physical 
life,  have  been  found  to  progress  in  integration,  in  hetero- 
geneity, in  definiteness.  It  is  not  enough  that,  in  the 
Special  Synthesis  just  closed,  intelligence  has  been  shown 
to  have  the  same  nature  and  the  same  law  from  the  lowest 
reflex  action  up  to  the  most  transcendent  triumph  of  reason ; 
and  that,  from  first  to  last,  its  growth  is  due  to  the  repetition 
of  experiences,  the  effects  of  which  are  accumulated,  organ- 
ized, and  inherited.  It  may  yet  be  asked — By  what  process 
is  the  organization  of  experiences  achieved?  Granting  that 
a  survey  of  the  facts  proves  it  to  take  place;  still,  no  an- 
swers are  given  to  the  questions — Why  does  it  take  place? 
And  how  does  the  transformation  which  brings  it  about 

come  within  the  formula  of  Evolution  in  general? 

507 


508  PHYSICAL  SYNTHESIS. 

Specifically  stated,  the  problem  is  to  interpret  mental 
evolution  in  terms  of  the  re-distribution  of  Matter  and 
Motion.  Though  under  its  subjective  aspect,  Mind  is 
known  only  as  an  aggregate  of  states  of  consciousness, 
which  cannot  be  conceived  as  forms  of  Matter  and  Motion, 
and  do  not  therefore  necessarily  conform  to  the  same  laws 
of  re-distribution;  yet  under  its  objective  aspect.  Mind  is 
known  as  an  aggregate  of  activities  manifested  by  an  or- 
ganism—is the  correlative,  therefore,  of  certain  material 
transformations,  which  must  come  within  the  general  pro- 
cess of  material  evolution,  if  that  process  is  truly  universal. 
Though  the  development  of  Mind  itself,  cannot  be  ex- 
plained by  a  series  of  deductions  from  the  Persistence  of 
Force,  yet  it  remains  possible  that  its  obverse,  the  develop- 
ment of  physical  changes  in  a  physical  organ,  may  be  so 
explained;  and  until  it  is  so  explained,  the  conception  of 
mental  evolution  as  a  part  of  Evolution  in  general,  remains 
incomplete. 

§  222.  Here,  then,  the  structure  and  functions  of  the 
nervous  system,  considered  as  resulting  from  intercourse 
between  the  organism  and  its  environment,  form  our  sub- 
ject-matter. We  have  to  identify  the  physical  process  by 
which  an  external  relation  that  habitually  affects  an  or- 
ganism, produces  in  the  organism  an  adjusted  internal 
relation. 

Of  course,  it  is  not  to  be  expected  that  specific  interpre- 
tations can  be  given  of  the  particular  structures  perform- 
ing particular  functions  which  fit  an  animal  to  its  particular 
conditions  of  existence.  All  we  can  hope  is  to  assign  a 
general  cause,  which,  acting  under  conditions  such  as  are 
known  to  exist,  is  capable  of  producing  effects  like  those 
observed.  Let  us  present  in  its  simplest  and  most  definite 
form  the  question  which  alone  admits  of  an  answer. 

We  have  seen  the  law  of  intelligence  to  be,  that  the 
strength  of  the  tendency  which  the  antecedent  of  any  psy- 


A  FURTHER  INTERPRETATION  NEEDED.     509 

chical  change  has  to  be  followed  by  its  consequent,  is  propor- 
tionate to  the  persistence  of  the  union  between  the  external 
things  they  symbolize.  We  have  seen  that  the  fulfilment  of 
this  law  is  accounted  for  if,  by  inheritance  through  successive 
organisms,  intelligence  grows,  as  it  does  in  the  individual  or- 
ganism, in  consequence  of  the  fact  that,  when  any  two  psy- 
chical states  occur  in  immediate  succession,  such  an  eif  ect  is 
produced  that  when  the  first  recurs,  there  is  a  tendency  for 
the  second  to  follow  it.  And  now,  to  complete  the  solution, 
we  have  to  ascertain  the  universal  principle  to  which  this 
tendency  is  due.  In  other  words,  regarding  psy- 

chical changes  as  the  subjective  faces  of  what  on  their  ob- 
jective faces  are  nervous  actions,  the  inquiry  before  us  is — 
from  what  general  law  of  the  re-distribution  of  Matter  and 
Motion  does  it  result,  that  when  a  wave  of  molecular  trans- 
formation passes  through  a  nervous  structure,  there  is 
wrought  in  the  structure  a  modification  such  that,  other 
things  equal,  a  subsequent  like  wave  passes  through  this 
structure  with  greater  facility  than  its  predecessor?  And — 
not  to  evade  a  still  deeper  question  which  immediately 
follows — is  the  establishment  of  nervous  communication  it- 
self explicable  on  this  same  general  principle?  Are  we 
enabled  by  it  to  understand  not  only  how  nerve  becomes 
more  permeable,  but  how  nerve  is  formed? 

If  to  these  general  questions  we  discover  a  satisfactory 
general  answer,  we  shall  do  all  that  is  needful.  If  from  a 
corollary  to  the  Persistence  of  Force,  we  can  legitimately 
draw  the  conclusion  that,  under  certain  conditions,  lines  of 
nervous  communication  will  arise,  and,  having  arisen,  will 
become  lines  of  more  and  more  easy  communication,  in  pro- 
portion to  the  numbers  and  strengths  of  the  discharges  pro- 
pagated through  them;  we  shall  have  found  a  physical 
interpretation  which  completes  the  doctrine  of  psychical 
evolution,  as  set  forth  in  the  last  two  parts.  It  will  be  made 
manifest  how  the  experience  of  an  external  relation  pro- 
duces a  corresponding  internal  relation — how,  as  experience 


510  PHYSICAL  SYNTHESIS. 

of  the  external  relation  become  more  numerous,  the  internal 
relation  becomes  more  coherent — how  perpetual  repetitions 
of  the  one  cause  indissolubleness  of  the  other — how  outer 
persistences  that  are  almost  or  quite  absolute,  establish,  in 
the  course  of  generations,  inner  cohesions  that  are  automatic 
or  organic;  and  thus  the  interpretation  of  instincts  and 
forms  of  thought  will  be  assimilated  to  that  of  the  ordinary 
phenomena  of  association.* 

*  The  general  doctrine  elaborated  in  the  succeeding  chapters,  was  pre> 
figured  in  the  first  edition  of  this  work,  in  a  note  on  page  544 — the  verbal 
form,  however,  being  such  as  I  should  not  now  use.  I  made  a  more  definite 
statement  of  it  in  an  article  published  in  the  Medico-Chirurgical  Review 
tor  January,  1859. 


CHAPTEK  n. 


THE    GENESIS    OF    NEKVES. 


§  223.  In  First  Principles^  Part  II.,  Chap.  IX.,  we  found 
that  in  all  cases,  motion  "  follows  the  line  of  greatest  trac- 
tion, or  the  line  of  least  resistance,  or  the  resultant  of  the 
two."  We  also  saw  "  that  motion  once  set  up  along  any  line 
becomes  itself  a  cause  of  subsequent  motion  along  that 
line  " — equally  when  the  motion  is  that  of  matter  through 
space,  that  of  matter  through  matter,  and  that  of  mole- 
cular undulations  through  an  aggregate  of  molecules. 

In  the  section  dealing  with  nervous  actions  (§  79),  it  was 
contended  that  the  mode  of  motion  we  distinguish  as  a 
nervous  discharge,  conforms  to  this  law.  "  Supposing  the 
various  forces  throughout  an  organism  to  be  previously  in 
equilibrium,  then  any  part  which  becomes  the  seat  of  a 
further  force,  added  or  liberated,  must  be  one  from  which 
the  force,  being  resisted  by  smaller  forces  around,  will  in- 
itiate motion  towards  some  other  part  of  the  organism.  If 
elsewhere  in  the  organism  there  is  a  point  at  which  force  is 
being  expended,  and  which  so  is  becoming  minus  a  force 
which  it  before  had,  instead  of  plus  a  force  which  it  before 
had  not,  and  thus  is  made  a  point  at  which  the  re-action 
against  surrounding  forces  is  diminished;  then,  manifestly, 
a  motion  taking  place  between  the  first  and  the  last  of  these 
points  is  a  motion  along  the  line  of  least  resistance.  Now  a 
sensation  implies  a  force  added  to,  or  evolved  in,  that  part 

of  the  organism  which  is  its  seat;  while  a  mechanical  move 

511 


512  PHYSICAL  SYNTHESIS. 

ment  implies  an  expenditure  or  loss  of  force  in  that  part  of 
the  organism  which  is  its  seat.  *  *  *  When  there  is 
anything  in  the  circumstances  of  an  animal's  life,  involving 
that  a  sensation  in  one  particular  place  is  habitually  followed 
by  a  contraction  in  another  particular  place — when  there  is 
thus  a  frequently-repeated  motion  through  the  organism  be- 
tween these  places;  what  must  be  the  result  as  respects  the 
line  along  which  the  motions  take  place?  Restoration  of 
equilibrium  between  the  points  at  which  the  forces  have 
been  increased  and  decreased,  must  take  place  through 
some  channel.  If  this  channel  is  affected  by  the  discharge 
— if  the  obstructive  action  of  the  tissues  traversed,  involves 
any  reaction  upon  them,  deducting  from  their  obstructive 
power;  then  a  subsequent  motion  between  these  two  points 
will  meet  with  less  resistance  along  this  channel  than  the 
previous  motion  met  with ;  and  will  consequently  take  this 
channel  still  more  decidedly." 

In  the  Prvnciples  of  Biology^  §  302,  this  general  proposi- 
tion was  further  elaborated.  It  there  became  needful  to 
indicate  a  possible  process  by  which,  among  other  tissues, 
nerve-tissue  arises  out  of  that  protoplasm  composing  the 
undifferentiated  organism.  Here,  in  an  abbreviated  form,  is 
the  argument  which  was  used : — "  It  is  to  be  inferred  that  a 
molecular  disturbance  in  any  part  of  a  living  animal,  set  up 
by  either  an  external  or  internal  agency,  will  almost  certain- 
ly disturb  and  change  some  of  the  surrounding  colloids  not 
originally  implicated — will  diffuse  a  wave  of  change  towards 
other  parts  of  the  organism :  a  wave  which  will,  in  the  ab- 
sence of  perfect  homogeneity,  travel  further  in  some  direc- 
tions than  in  others.  Let  us  ask  next  what  will  determine 
the  differences  of  distance  travelled  in  different  directions. 
Obviously  any  molecular  agitation  spreading  from  a  centre, 
will  go  furthest  along  routes  that  offer  least  resistance. 
What  routes  will  these  be?  Those  along  which  there  lie 
most  molecules  that  are  easily  changed  by  the  diffused 
molecular  motion,  and  which  yet  do  not  take  up  much 


THE  GENESIS  OP  NERVES.  613 

molecular  motion  in  assmning  their  new  states.  *  *  * 
Unstable  molecules  which,  in  being  isomerically  trans- 
formed, do  not  absorb  motion,  and  still  more  those  which, 
in  being  so  transformed,  give  out  motion,  will  readily  pro- 
pagate any  molecular  agitation;  since  they  will  pass  on  the 
impulse  either  undiminished,  or  increased,  to  adjacent  mole- 
cules. *  *  *  It  may  be  concluded  that  any  molecular 
agitation  set  up  by  what  we  call  a  stimulus,  will  diffuse 
itself  further  along  some  lines  than  along  others,  if  "  the 
mingled  colloids  forming  "  the  protoplasm  are  not  quite 
homogeneously  dispersed,  and  if  some  of  them  are  isomeric- 
ally transformed  more  easily,  or  with  less  expenditure  of 
motion,  than  others;  and  it  will  especially  travel  along 
spaces  occupied  chiefly  by  those  molecules  which  give  out 
molecular  motion  during  their  metamorphoses,  if  there 
should  be  any  such.  *  *  *  As  is  shown  by  those 
transformations  that  so  rapidly  propagate  themselves 
through  colloids,  molecules  that  have  undergone  a  certain 
change  of  form,  are  apt  to  communicate  a  like  change  of 
form  to  adjacent  molecules  of  the  same  kind — the  impact 
of  each  overthrow  is  passed  on  and  produces  another  over- 
throw, *  *  *  Is  this  action  limited  to  strictly  isomeric 
substances?  or  may  it  extend  to  substances  that  are  closely 
allied?  *  *  *  There  is  reason  to  suspect  that  it  does. 
Already  when  treating  of  the  nutrition  of  parts,  it  was 
pointed  out  that  we  are  obliged  to  recognize  a  power  pos- 
sessed by  each  tissue  to  build  up,  out  of  the  materials 
brought  to  it,  molecules  of  the  same  type  as  those  of  which 
it  is  formed.  *  *  *  If  this  be  a  general  principle  of 
tissue-growth  and  repair,  we  may  conclude  that  it  will 
apply  in  the  case  before  us.  A  wave  of  molecular  disturb- 
ance passing  along  a  tract  of  mingled  colloids  closely  allied 
in  composition,  and  isomerically  transforming  the  molecules 
of  one  of  them,  will  be  apt  at  the  same  time  to  form  some 
new  molecules  of  the  same  type,  at  any  place  where  there 
exist  the  proximate  components,   either  uncombined   or 


514  PHYSICAL  SYNTHESIS. 

feebly  combined  in  some  not  very  different  way.  *  *  * 
That  is  to  say,  a  wave  of  molecular  disturbance  diffused 
from  a  centre,  and  travelling  furthest  along  a  line  where  lie 
most  molecules  that  can  be  isomerically  transformed  with 
facility,  will  be  likely  at  the  same  time  to  further  differen- 
tiate this  line,  and  make  it  more  characterized  than  before 
by  the  easy-transformability  of  its  molecules." 

Referring  the  reader  to  the  Princvplea  of  Biology  for  the 
details  and  conclusion  of  this  abridged  argument,  it  may  be 
well  to  remind  him  that  in  the  first  part  of  this  work,  the 
interpretations  of  nerve-structure  and  nerve-function  were 
grounded  on  a  conception  which  is  a  corollary  from  the 
conception  recalled  above;  and  that  sundry  verifications 
were  there  found.  We  saw  that  the  quantity  of  effect  pro- 
duced by  irritated  nerve-fibre,  increases  with  the  distance 
between  the  place  of  irritation  and  the  place  of  discharge; 
and  this  accumulation  of  force  we  found  to  be  just  that 
which  would  result  from  a  wave  of  isomeric  transformation 
through  matter  of  the  required  kind  (§  19).  We  saw,  too, 
that  the  ultimate  nitrogenous  nerve-threads  are  severally 
sheathed  in  a  peculiar  substance,  which,  judging  by  its  un- 
equalled molecular  complexity,  is  less  capable  than  any 
other  known  substance  of  transferring  molecular  motion, 
and  therefore  best  fitted  to  prevent  lateral  loss  of  that 
growing  wave  of  molecular  motion  which  a  nerve-fibre 
transmits.  And  we  further  saw  that  a  close  analogy  exists 
between  this  assumed  propagation  of  isomeric  change  along 
a  nerve-fibre,  and.  certain  observed  propagations  of  like 
changes  along  fibres  of  other  substances  (§  34).  To  which 
let  me  here  add  the  fact  that  protoplasm  and  its  derivatives 
are  distinguished  by  the  great  number  of  their  isomeric 
forms,  and  the  great  facility  with  which  these  are  changed 
by  very  various  agents;  so  that  in  regarding  a  nervous  dis- 
charge as  a  wave  of  isomeric  transformation,  we  are  regard- 
ing it  as  one  out  of  the  many  such  transformations  which 
living  matter  continually  undergoes. 


THE  GENESIS  OF  NERVES.  515 

§  224.  Another  preliminary  step  remains.  We  have 
to  observe  the  possible  modes  in  which  a  line  of  nervous 
communication  may  be  improved.  When,  through  undif- 
ferentiated tissue,  there  has  passed  for  the  first  time  a  wave 
of  disturbance  from  some  place  where  molecular  motion  is 
liberated  to  some  place  where  it  is  absorbed,  the  line  of 
least  resistance  followed  must  be  an  indefinite  and  irregular 
one.  Fully  to  understand  the  genesis  of  nerve,  then,  we 
must  understand  the  physical  actions  which  change  this 
vague  course  into  a  definite  channel,  that  becomes  ever  more 
permeable  as  it  is  more  used. 

Several  actions  conduce  to  this  result.  The  first  is  that 
already  described,  by  which,  along  a  line  of  discharge, 
there  is  a  genesis  of  the  matter  most  capable  of  com- 
municating the  discharge.  Every  time  an  incipient  nerve 
is  traversed  by  another  wave  of  molecular  motion,  there  is 
apt  to  be  a  further  formation  of  the  molecules  which  are 
isomerically  transformed  by  the  wave  and  pass  it  on  in  being 
transformed.  This  process  acts  with  continually-increasing 
power,  for  two  reasons.  One  is  that  progressing 

limitation  of  the  wave  to  a  well-marked  line,  enables  it  to 
produce  more  decided  effects  along  that  line.  An  illustra- 
tion will  here  help  us.  When  a  body  of  water  flows  over  a 
surface  offering  no  distinct  course,  it  thins  out  into  wide- 
spread shallows  near  its  margin,  where  it  is  almost  motion- 
less; and  it  has  but  little  motion  even  along  its  central 
deepest  parts.  But  if  the  inundation  is  long  continued,  the 
abraiding  action  of  the  current  along  these  central  deepest 
parts  where  it  moves  fastest,  tends  to  deepen  its  channel 
there  more  than  elsewhere.  A  secondary  result  is  a  retreat 
of  the  water  from  the  shallows — the  current  becomes  more 
concentrated.  In  proportion  as  it  becomes  more  concen- 
trated the  force  of  its  central  part  becomes  greater  still,  and 
the  deepening  more  rapid ;  which  entails  a  further  drawing 
in  of  the  margins  and  a  further  addition  to  the  excavating 

force.      So  that  the  growing  definiteness  of  the  current 
84 


616  PHYSICAL  SYNTHESIS. 

brings  a  growing  power  of  making  its  channel  quite  definite. 
Now  though  in  the  case  before  us  we  have  not  a  motion  of 
matter  over  matter,  but  a  transfer  of  molecular  motion  from 
molecules  to  molecules,  the  parallel  holds.  Any  greater 
effect  produced  by  the  transfer  along  one  part  of  ita 
originally-broad  course,  similarly  tends  to  concentrate 
the  transfer  along  this  part,  and  thus  to  intensify  the 
action  which  makes  this  part  a  precisely-marked  chan- 
nel. A  further  facilitation  results  from  an  absolute 
increase  in  the  amount  of  the  nervous  discharge.  The  more 
permeable  the  line  of  molecules  becomes,  the  greater  be- 
comes the  initial  quantity  of  molecular  motion  it  draughts 
off.  As  with  water,  the  formation  of  a  definite  channel  not 
only  makes  the  transfer  easier  and  adds  to  the  excavating 
power  of  the  current,  supposing  its  volume  be  constant,  but 
also  (if  the  reservoir  can  supply  more)  augments  the  volume 
carried  away,  which  again  adds  to  the  excavating  power; 
80  the  formation  of  a  better  line  of  nervous  communication 
is  followed  by  an  increase  of  the  wave  that  sets  out  to 
traverse  it,  and  a  consequent  increase  in  the  channel-making 
action.  Once  more,  every  addition  to  the  mole- 
cular motion  transmitted,  adds  to  the  effectiveness  of  each 
discharge  in  overcoming  an  obstacle.  Suppose  the  greater 
part  of  its  channel  has  become  tolerably  permeable,  but  that 
at  some  place  in  it  the  colloidal  matter  is  less  transformed 
than  elsewhere  into  the  fit  type.  Then  the  more  the  rest  of 
its  channel  increases  in  permeability,  the  more  powerful 
must  be  the  wave  of  molecular  motion  brought  to  bear  on 
the  untransf  ormed  part,  and  the  greater  must  be  the  tenden- 
cy to  transform  it.  Hence  the  channel  will  progress  towards 
a  state  of  uniform  permeability. 

There  is  another  possible,  and  I  think  probable,  way  in 
which  the  passage  of  a  nervous  discharge  is  made  easier. 
The  molecules  of  the  peculiar  colloid  composing  a  nerve, 
may  be  either  irregularly  arranged  or  regularly  arranged; 
and  if  irregularly  arranged  they  will  transmit  a  wave  of 


THE  GENESIS  OF  NERVES.  517 

molecular  motion  less  readily  than  if  regularly  arranged. 
Now  when  a  thread  of  molecules  capable  of  the  required 
easy  isomeric  transformation  is  first  formed,  the  probabilities 
are  infinity  to  one  that  adjacent  molecules  will  be  unsym- 
metrically  placed  with  respect  to  one  another — they  will  not 
stand  in  polar  order.  Molecules  that  are  highly  complex 
and  massive,  either  do  not  crystallize  at  all  or  crystallize 
with  great  difficulty.  Either  their  colloidal,  non-polar 
arrangement  is  a  permanent  one,  or  it  is  one  out  of  which 
they  pass  into  a  polar  arrangement  very  slowly,  under 
special  conditions.  Nevertheless,  molecules  of  every  type 
have  a  form  of  distribution  in  which  their  polar  forces  are 
in  equilibrium.  Towards  this  they  must  ever  tend,  however 
feebly;  and  towards  this  every  slight  molecular  disturbance 
enables  them  to  approach.  Hence,  if  through  a  line  of 
colloidal  molecules  wholly  out  of  polar  arrangement,  there 
pass  successive  waves  of  molecular  motion,  each  will  help 
adjacent  molecules  towards  polar  arrangement,  or  state  of 
equilibrium.    Let  us  consider  the  concomitants. 

To  aid  our  conceptions  we  will  as  before  (§19)  take  the 
rude  analogy  furnished  by  a  row  of  bricks  on  end,  which 
overthrow  one  another  in  succession.  If  such  bricks  on  end 
have  been  adjusted  so  that  their  faces  are  all  at  right  angles 
\  to  the  line  of  the  series,  the  change  will  be  propagated  along 
them  with  the  least  hindrance;  or,  under  certain  conditions, 
with  the  greatest  multiplication  of  the  original  impulse. 
For  when  so  placed,  the  impact  each  brick  gives  to  the  next, 
being  exactly  in  the  line  of  the  series,  will  be  wholly  effec- 
tive ;  but  when  they  are  otherwise  placed  it  will  not.  If  the 
bricks  stand  with  their  faces  variously  askew,  each  in  falling 
will  have  a  motion  more  or  less  diverging  from  the  line  of 
the  series;  and  hence  only  a  part  of  its  momentum  will 
impel  the  next  in  the  required  direction.  Now  though  in 
the  case  of  a  series  of  molecules  the  action  can  be  by  no 
means  so  simple,  yet  the  same  principle  holds.  The  isomeric 
change  of  a  molecule  must  diffuse  a  wave  which  is  greater 


518  PHYSICAL  SYNTHESIS. 

in  some  one  direction  than  in  all  others.  If  so,  there  are 
certain  relative  positions  of  molecules  such  that  each  will 
receive  the  greatest  amount  of  this  wave  from  its  predecessor, 
and  will  so  receive  it  as  most  readily  to  produce  a  like  change 
in  itself.  A  series  of  molecules  thus  placed  must  stand  in 
symmetrical  relations  to  one  another — polar  relations.  And 
it  is  not  difficult  to  see  that,  as  in  the  case  of  the  bricks,  any 
deviation  from  symmetrical  or  polar  relations  will  involve 
a  proportionate  deduction  from  the  efficiency  of  the  shock, 
and  a  diminution  in  the  quantity  of  molecular  motion  given 
out  at  the  far  end.  But  now,  what  is  the  indirect 

result  when  a  wave  of  change  passes  along  a  line  of  mole- 
cules thus  unsymmetrically  placed?  The  indirect  result  is 
that  the  motion  which  is  not  passed  on  by  the  unsymmetri- 
cally-placed  molecules,  goes  towards  placing  them  sym- 
metrically. Let  us  again  consider  what  happens  with  our 
row  of  bricks.  When  one  of  these  in  falling  comes  against 
tiie  next,  standing  askew,  its  impact  is  given  to  the  nearest 
angle  of  this  next,  and  so  tends  to  give  this  next  a  motion 
round  its  axis.  Further,  when  the  next  thus  moved  delivers 
its  motion  to  its  successor,  it  does  this  not  through  the  angle 
on  the  side  that  was  struck,  but  through  the  diagonally- 
opposite  angle;  and,  consequently,  the  reaction  of  its  impact 
on  its  successor  adds  to  the  rotatory  motion  already  re- 
ceived. Hence  the  amount  of  force  which  it  does  not  pass 
on,  is  the  amount  of  force  absorbed  in  turning  it  towards 
parallelism  with  its  neighbours.  Similarly  with  the  mole- 
cules. Each  in  falling  into  its  new  isomeric  attitude,  and 
passing  on  the  shock  to  its  successor,  gives  to  its  successor 
a  motion  which  is  all  passed  on  if  the  successor  stands  in 
polar  relation  towards  it,  but  which,  if  the  relation  is  not 
polar,  is  only  partially  passed  on — some  of  it  being  taken  up 
in  moving  the  successor  towards  a  polar  relation.  One 

more  consequence  is  to  be  observed.  Every  approach  of  the 
molecules  towards  symmetrical  arrangement,  increases  the 
amount  of  molecular  motion  transferred  from  one  end  of  the 


THE  GENESIS  OP  NERVES.  519 

series  to  the  other.  Suppose  that  the  row  of  bricks,  which 
were  at  first  very  much  out  of  parallelism^  have  fallen,  and 
that  part  of  the  motion  given  by  each  to  the  next  has  gone 
towards  bringing  their  faces  nearer  to  parallelism;  and  sup- 
pose that,  without  further  changing  the  positions  of  their 
bases,  the  bricks  are  severally  restored  to  their  vertical  atti- 
tudes; then  it  will  happen  that  if  the  serial  overthrow  of 
them  is  repeated,  the  actions,  though  the  same  as  before  in 
their  kinds,  will  not  be  the  same  as  before  in  their  degrees. 
Each  brick,  falling  as  it  now  does  more  in  the  line  of  the 
series,  will  deliver  more  of  its  momentum  to  the  next;  and 
less  momentum  will  be  taken  up  in  moving  the  next  towards 
parallelism  with  its  neighbours.  If,  then,  the  analogy  holds, 
it  must  happen  that  in  the  series  of  isomerically-changing 
molecules,  each  transmitted  wave  of  molecular  motion  is 
expended  partly  in  so  altering  the  molecular  attitudes  as 
to  render  the  series  more  permeable  to  future  waves,  and 
partly  in  setting  up  changes  at  the  end  of  the  series;  that 
in  proportion  as  less  of  it  is  absorbed  in  working  this  struc- 
tural change,  more  of  it  is  delivered  at  the  far  end  and 
greater  effect  produced  there;  and  that  the  final  state  is 
one  in  which  the  initial  wave  of  molecular  motion  is  trans- 
mitted without  deduction — or  rather,  with  the  addition  of 
the  molecular  motion  given  out  by  the  successive  molecules 
of  the  series  in  their  isomeric  falls. 

§  225.  From  beginning  to  end,  therefore,  the  develop- 
ment of  nerve  results  from  the  passage  of  motion  along  the 
line  of  least  resistance,  and  the  reduction  of  it  to  a  line  of 
less  and  less  resistance  continually.  The  first  opening  of  a 
route  along  which  equilibrium  is  restored  between  a  place 
where  molecular  motion  is  in  excess  and  a  place  where  it  is 
in  defect,  comes  within  this  formula.  The  production  of  a 
more  continuous  line  of  that  peculiar  colloid  best  fitted  to 
transmit  the  molecular  motion,  also  comes  within  this  for- 
mula ;   as  does  likewise  the  making  of  this  line  thicker  and 


520  PHYSICAL  SYNTHESIS. 

more  even.  And  the  formula  also  covers  that  final  process 
by  which  the  line,  having  been  formed,  has  its  molecules 
brought  into  the  polar  order  which  least  resists,  and  indeed 
facilitates,  the  transmission  of  the  wave. 

§  225a.  Some  qualifications  of  the  foregoing  exposition 
must  now  be  made.  Instead  of  changing  it  throughout  to 
meet  criticisms,  I  have  thought  it  best  to  repeat  the  exposi- 
tion as  given  in  the  second,  third,  and  fourth  editions  of  this 
work  and  then  to  indicate  the  needful  modifications. 

At  the  meeting  of  the  British  Association  held  in  Belfast 
in  1874,  Prof.  Clerk-Maxwell  objected  to  the  hypothesis  that 
the  nerve-current  consists  of  successive  waves  of  isomeric 
change,  on  the  ground  that  the  implied  conception  was  that 
of  a  "  heat-machine,"  and  that  a  heat-machine  is  impossible 
in  the  absence  of  difference  of  temperature.  In  reply,  I  con- 
tended that  my  hypothesis  is  not  at  variance  with  this  law 
of  thermo-dynamics,  since  it  supposes  that  the  falling  of  each 
molecule  from  one  isomeric  form  to  another  is  accompanied 
by  absorption  of  heat,  and  that  the  nerve-fibre,  thereupon 
rendered  of  lower  temperature  than  the  surrounding  mat- 
ters, instantly  takes  up  from  them  heat  sufficient  to  cause  the 
molecules  to  resume  their  previous  form:  the  implication 
being  that  the  nerve-current  is  at  the  cost  of  the  heat  yielded 
by  the  imbedding  tissues.  The  discussion  which  ensued 
failed  to  draw  from  Prof.  Clerk-Maxwell  the  admission  that 
my  reply  was  adequate,  and  failed  also  to  make  me  under- 
stand his  difficulty.  This  difficulty,  as  since  explained  to  me 
by  Lord  Rayleigh,  is  that,  being  a  lower  form  of  molecular 
motion,  heat  cannot  reproduce  that  higher  form  of  molecular 
motion  implied  by  the  hypothesis.  Here  I  have  no  alter- 
native but  to  accept  the  dicta  of  these  two  distinguished 
physicists.  It  is  true  that  the  heat  supplied  by  a  sitting  hen 
apparently  suffices  to  build  up  a  variety  of  complex  com- 
pounds, some  of  which,  as  protagon,  are  more  complex  than 
any  of  those  contained  in  the  unorganized  materials  of  the 


THE  GENESIS  OF  NERVES.  620* 

egg;  and  it  miglit  seem  a  fair  inference  that  such  being  the 
case,  heat  must  be  capable  of  raising  a  molecule  of  protein 
from  a  lower  isomeric  form  to  a  higher.  But  I  suppose 
there  must  be  some  lack  of  parallelism  between  the  two  cases, 
and  that  this  rhythmical  isomeric  change  iu  nerve-fibre 
implies  some  further  physical  process  which  ultimate  physic- 
al principles  negative. 

What  qualification  then  must  the  hypothesis  undergo  to 
render  it  tenable?  Apparently  we  must  conclude  that  in 
nerve-fibre,  as  in  the  tissues  at  large,  performance  of  func- 
tion is  accompanied  by  molecular  disintegration,  and  that 
fitness  for  subsequent  performance  of  function  is  to  be 
gained  only  by  re-integration.  The  implication  would  seem 
to  be  that  the  molecular  change  must  be,  to  some  extent,  a 
chemical  change ;  and  that  each  molecule  which  has  under- 
gone modification,  has  to  be  repaired  by  absorption  of  need- 
ful matter  from  the  nutrient  liquid  with  which  it  is  bathed. 

This  supposition  appears  congruous  with  the  fact  that  the 
axis-cylinder  of  a  nerve-fibre,  small  in  diameter  though  it  is, 
consists  of  a  bundle  of  still  more  minute  fibres.  It  seems 
not  unlikely  that  such  component  fibres  as  have  conveyed  a 
wave  of  nerve-change,  and  become  thereby  temporarily  in- 
capacitated, have  their  functions  undertaken  by  another 
cluster  of  component  fibres,  which  carry  the  next  wave,  and 
these,  again,  leave  the  function  to  be  afterwards  performed 
by  a  third  cluster,  and  so  on:  the  fibres  of  the  first  cluster 
having  meanwhile  refitted  themselves  for  activity.  If  so, 
there  is  a  parallelism  between  the  action  of  nerves  and  the 
action  of  muscles;  in  which  last  the  sets  of  fibres  take  their 
turns  of  action  and  rest,  while  the  muscle  as  a  whole  con- 
tinues in  a  state  of  contraction. 


CHAPTER  ni. 

THE    GENESIS    OF    SIMPLE  NERVOUS    SYSTEMS.* 

§  226.  Careful  and  extended  observations  have  necessi- 
tated changes  in  the  cell-doctrine  as  originally  propounded. 
The  statement  that  all  organisms  of  sensible  sizes  are  made 
up  of  minute  nucleated  bodies,  completely  distinct  from  one 
another,  has  to  be  much  qualified. 

Among  botanists  a  wide  change  of  view  resulted  from  the 
discovery  that  in  the  tissues  of  plants  the  protoplasm  within 
each  cell  is  united  to  that  within  adjacent  cells  by  threads  of 
protoplasm  which  pass  through  the  respective  cell-walls:  a 
discovery  that  at  once  makes  more  comprehensible  various 
plant-movements.  Implying  a  kindred  structure.  Prof. 
Sedgwick  writes : — "  It  is  becoming  more  and  more  clear 

*  In  his  Inaugural  Address  to  the  Section  of  Anatomy  and  Physiology, 
at  the  meeting  of  the  British  Association  in  1880,  Prof.  Balfour,  after  indi- 
cating certain  new  lights  thrown  on  the  evolution  of  nervous  systems, 
remarked  concerning  the  contents  of  this  chapter : — "  These  hypotheses  of 
Herbert  Spencer,  which  have  been  widely  adopted  in  this  country,  are,  it 
appears  to  me,  not  borne  out  by  the  discoveries  to  which  I  have  called 
your  attention  to-day."  Being,  as  1  considered,  bound  to  accept  Prof. 
Balfour's  representations,  I  was  about  to  change  essentially  the  first  part 
of  this  chapter,  when  my  attention  was  drawn  to  an  opinion  since  pub- 
lished by  Prof.  Adam  Sedgwick,  the  successor  of  Prof.  Balfour  in  the 
same  chair  at  Cambridge.  The  opinion  in  question  is  contained  in  A 
Monograph  of  the  Development  of  Peripatus  Capensis,  p.  49,  and  is  ex- 
pressed as  follows : — "  Herbert  Spencer's  view  of  the  origin  of  the  nervous 
system  may  perhaps  not  be  so  far  from  the  mark  as  at  first  sight  ap- 
peared." Taking  advantage  of  the  recent  results  of  histological  researches^ 
I  have  been  led,  by  the  criticism  and  counter-criticism  above  quoted,  to 
re-cast  the  early  part  of  this  chapter,  and  to  give  the  contained  hypothesis 
a  more  satisfactory  form,  I  think,  than  previously  seemed  possible. 

6206 


THE  GENESIS  OP  SIMPLE  NERVOUS  SYSTEMS.    520e 

every  day  that  the  cells  composing  the  tissues  of  animals  are 
not  isolated  units,  but  that  they  are  connected  with  one 
another.  I  need  only  refer  to  the  connection  known  to  exist 
between  connective  tissue  cells,  cartilage  cells,  epithelial 
cells,  &c.  And  not  only  may  the  cells  of  one  tissue  be  con- 
tinuous with  each  other,  but  they  may  also  be  continuous 
with  the  cells  of  other  tissues  "  (pp.  47-8). 

The  revised  conception  to  which  we  are  thus  introduced, 
is  that  throughout  those  aggregations  of  Protozoa  by  which 
Metazoa  have  been  formed,  there  has  been  an  incompleteness 
of  those  spontaneous  fissions  which,  if  complete,  would  have 
multiplied  the  Protozoa :  the  units  have  remained  connected 
by  prolongations  homologous  with  pseudopodia.  As  the 
members  of  a  compound  Rhizopod,  say  one  of  the  Foramini- 
fera,  are  not  wholly  cut  off  from  one  another,  but  maintain 
some  continuity  of  substance  through  perforations  in  the 
septa — as  the  living  units  which  make  up  a  Vohox  or  a 
Raphidwpkrys  are  held  together  by  threads  of  protoplasm 
which  traverse  their  respective  limiting  membranes;  so  it 
appears  that  segmentatior  in  a  fertilized  ovum  does  not  abso- 
lutely isolate  the  contained  matter  of  each  segment.  In  the 
ovum  of  Peripatus^  at  any  rate,  which  is  exceptionally  adapted 
for  displaying  the  early  changes,  there  results  a  network  of 
protoplasm  which  unites  the  cell-masses  with  one  another. 
And  Prof.  Sedgwick,  saying  that  in  Peripatus  "  the  connec- 
tion of  cell  with  cell  is  not  a  secondary  feature  acquired  late 
in  development,  but  is  primary,"  leans  to  the  conclusion  that 
"  the  continuity  in  the  various  cells  of  the  adult  "  is  "  due  to 
a  primitive  continuity  which  has  never  been  broken  "  (p.  49). 

Thus,  then,  we  must  conceive  of  animal  tissue  as  having 
from  the  beginning  consisted  of  a  matrix  of  relatively  inert 
substances  throughout  which  there  runs  a  nucleated  net- 
work of  living  and  active  protoplasm. 

§  226a,  As  shown  in  the  actions  of  a  Rhizopod,  proto- 
plasm displays  at  once  the  properties  of  nerve  and  muscle ;  it 


520<?  PHYSICAL  SYNTHESIS. 

conducts  and  it  contracts.  These  united  properties  still 
characterize  it  when  it  assumes  the  form  of  an  imbedded  net- 
work. That  it  continues  to  possess  them  when  permeating 
vegetal  tissues  is  proved  by  such  actions  as  those  of  the 
Sensitive  Plant  and  the  Dioncea — actions  which  show  us 
both  the  conveyance  of  a  disturbance  and  the  production  of 
movement  at  a  distance.  And  that  the  protoplasmic  net- 
work of  animal  tissue  has  the  like  combined  traits  we  see  in 
such  simple  types  as  the  Hydra, 

Observe,  next,  that  these  properties  are  most  markedly 
displayed  where  the  protoplasm  exists  in  an  elongated  form. 
If  the  tentacle  of  a  polype  is  touched  it  contracts  with 
tolerable  promptness — with  greater  promptness  than  the 
body  contracts.  Among  the  oceanic  Hydrozoa  which,  float- 
ing or  swimming,  have  long  pendant  tentacles,  such  as 
Diphyes  and  Physalia,  the  threads  of  nucleated  sarcode  thus 
trailing  behind  or  hanging  down,  are  quickly  drawn  up  when 
struck  by  small  creatures  serving  for  prey.  These  traits  are 
in  great  measure  cause  and  consequence.  Molecular  change 
set  up  at  the  end  of  a  thread-shaped  portion  of  substance  is 
necessarily  limited  to  the  line  formed  by  the  substance.  It 
cannot  be  lost  by  diffusion  through  a  large  mass  like  that  of 
the  body,  but  must  be  concentrated  within  the  channel 
formed  by  the  sides  of  the  thread. 

This  much  premised,  let  us  now  ask  what  will  result  in  the 
body  of  a  creature  which  is  as  yet  but  little  differentiated? — 
what  will  happen  to  the  nucleated  network  of  protoplasm 
diffused  through  it?  From  the  general  law  of  the  instability 
of  the  homogeneous,  it  is  to  be  inferred  that  the  originally- 
united  properties  of  protoplasm  will  not  remain  the  same 
throughout.  "We  may  expect  a  specialization  such  as  will 
restrict  the  contractile  power  to  some  parts  of  it  and  leave 
the  power  of  conduction  to  other  parts.  How  will  this 
differentiation  be  likely  to  arise?  Suppose  the  incipiently- 
organized  mass  to  be  from  time  to  time  rudely  disturbed  by 
passing  bodies — How  will  the  effects  of  the  shocks  be 


THE  GENESIS  OF  SIMPLE  NERVOUS  SYSTEMS.     521 

localized?  May  we  not  reasonably  say  that  the  parts  of 
the  protoplasmic  network  which  become  contractile,  will  be 
those  of  which  the  contraction  is  least  resisted;  and,  con- 
versely, that  the  parts  which  cannot  contract  without  greater 
resistance  will  remain  conductive  only.  So  far  as  ascertained, 
the  facts  harmonize  with  this  supposition.  Muscular  fibres 
first  make  their  appearance  as  processes  of  the  epithelial 
cells  forming  the  surface  of  the  body  (see  Balfour's  Embry- 
ology, vol.  II.  p.  667);  and  this  is  the  part  in  which  move- 
ment is  least  resisted,  since  the  inert  matter  on  one  side  only 
of  the  layer,  has  to  be  carried  along  with  the  contracting  ele- 
ments. Conversely,  though  the  primitive  nervous  elements, 
being  the  recipients  of  external  impressions,  first  arise  on  the 
outer  surface,  yet  the  protoplasmic  network  connected  with 
them,  which  takes  on  the  function  of  conducting  impres- 
sions, soon  becomes  established  below  the  surface :  contrac- 
tion in  this  part  of  the  network  being  opposed  by  inert  tissue 
imbedding  the  fibres  on  all  sides,  and  the  assumption  of  con- 
ducting function  solely  being  hence  favoured. 

A  further  question  now  presents  itself — By  what  physical 
process  is  the  functional  relation  established  between  these 
muscular  and  nervous  elements  as  fast  as  they  differentiate? 
There  is  a  not  unsatisfactory  answer.  A  portion  of  tissue 
which,  by  disturbance  of  one  or  other  kind,  has  been  made 
to  contract,  is  a  portion  in  which  molar  motion  has  been  pro- 
duced at  the  cost  of  molecular  motion :  the  one  implies  the 
other.  Contrariwise,  a  portion  of  tissue  which,  by  some 
incident  force  or  stimulus,  has  been  disturbed,  but  does  not 
undergo  contraction,  is  one  in  which  the  molecular  motion 
generated  remains  free.  In  the  first  place,  then,  there  iscaused 
a  deficiency,  and  in  the  second  place  there  is  caused  a  surplus. 
Consequently  if,  between  the  two,  there  is  any  channel 
through  which  an  equilibrium  can  be  established,  a  flow  of 
molecular  motion  through  it  may  be  anticipated.  Such  a 
channel  exists  in  the  protoplasmic  network.  Hence,  when 
the  incipiently-differentiating  tissues  are  disturbed,  there  will 


622  ^  PHYSICAL  SYNTHESIS. 

result  a  draught  from  the  portion  which  is  beginning  to  act 
as  a  sensory  organ  to  the  portion  which  is  beginning  to  act  as 
a  contractile  organ — a  draught  which,  repeated  on  each  occa- 
sion, will,  in  conformity  to  the  principle  set  forth  in  the  last 
chapter,  tend  ever  to  make  the  channel  more  permeable. 

And  then,  lastly,  observe  that  though  there  is  implied 
a  simultaneity  in  the  production  of  the  deficiency  and  the 
surplus  in  the  case  described,  so  that  the  contraction  has 
already  arisen  at  the  time  that  the  stimulus  has  been  received, 
yet  it  is  inferable  that  when  the  connecting  channel  has 
become  easily  permeable,  the  reception  of  a  stimulus  will 
cause  a  flow  through  the  channel,  and  consequent  arrival 
at  the  contracting  part  before  this  has  been  otherwise  dis- 
turbed: the  result  being  that  the  surplus  molecular  motion 
received  will  initiate  a  contraction.  Sensation,  or  that  which 
corresponds  to  it,  will  produce  motion  through  incipient 
nerves. 

§  227.  In  many  coelenterate  creatures  the  contractile 
substance  is  partly  differentiated  into  muscular  fibres;  which, 
however,  are  distributed  in  a  diffused  way.  In  an  Actinia^, 
the  average  equality  of  the  forces  to  which  the  body  is  ex- 
posed all  round,  is  unfavourable  to  the  formation  of  distinct 
muscles  and  a  distinct  nervous  system.  There  is  nothing 
which  tends  to  bring  the  contractility  to  one  place;  and 
therefore  nothing  which  causes  the  waves  of  molecular  dis- 
turbance to  take  special  courses.  Probably  in  a  sea-anemone, 
the  incipient  lines  of  nervous  discharge  are  as  much  diffused 
as  the  muscular  fibres  are  diffused.  Noting  only  the  fact 
that  the  contractile  tissue  which,  when  it  acts,  absorbs 
molecular  motion,  becomes  differentiated  hefore  there  arise 
distinct  nerve-fibres  conveying  molecular  motion  from  places 
whereithasbeenevolved,let  us  take  a  hypothetical  case  fitted 
to  make  intelligible  the  first  step  in  nervous  development. 

Suppose  that  the  process  of  continuous  gemmation,  by 
which  creatures  of  these  low  types  very  generally  multiply, 
is  so  carried  on  that  the  individuals  successively  produced 


THE  GENESIS  OF  SIMPLE  NERVOUS  SYTEMS.       523 


are  interfered  with  by  the  colony  more  on  one  side  than  on 
the  other  side.    Being  nnsymmetrically  conditioned  they  will 

become  unsymmetrically 
developed.  {Prinovples 
of  Biology  §§246,247.) 
Let  Fig.  5  represent  a 
creature  of  this  kind  that 
grows  obliquely  away 
from  its  elder  neighbours; 
and  let  A  B  stand  for 
the  surface  over  which 
the  colony  is  spreading. 
Then  it  must  happen  that 
when  moving  objects  in  the  adjacent  water,  larger  than 
those  minute  ones  serving  for  prey,  come  against  the 
creature,  first  striking  its  expanded  tentacles  and  then  its 
body,  the  most  exposed  part  of  its  body  C  will  be  most  fre- 
quently disturbed.  Each  time  it  is  disturbed  there  will  be 
propagated  through  it  that  form  of  molecular  change  from 
which  contraction  results,  and  there  will  occasionally  be 
produced  more  molecules  of  this  same  type.  {Prmciples  of 
Biology  §  302.)  That  is  to  say  C  will  become  a  place  where 
the  contractions  are  relatively  frequent  and  decided,  and 
where  contractile  protoplasm  is  greater  in  amount  than  else- 
where. What  further  will  happen  ?  Mostly  when  a  collision 
occurs  the  tentacles  are  touched  before  the  body;  and,  for 
reasons  above  given,  the  propagation  of  molecular  change 
along  them  is  comparatively  rapid.  N^ow  at  the  part  C,  each 
evolution  of  mechanical  motion  is  necessarily  accompanied 
by  an  absorption  of  molecular  motion.  Consequently  when 
from  the  disturbed  end  of  the  tentacle  D  there  has  been 
sent  a  wave  of  molecular  motion,  part  of  which  is  absorbed 
in  the  contraction  of  each  successive  portion  of  the  tentacle 
but  a  surplus  of  which  passes  on,  setting  up  contractions  of 
the  portions  below,  the  final  surplus  when  the  wave  has 
reached  d,  will  be  drafted  off  to  the  contractile  portion  C; 


624  PHYSICAL  SYNTHESIS. 

since  this,  being  struck  the  instant  after,  and  made  to  con- 
tract, becomes  a  place  where  molecular  motion  is  absorbed. 
But  such  an  action  does  not  constitute  a  true  nervous  ac- 
tion. For  the  stimulus  applied  at  D  is  not  the  cause  of  the 
contraction  at  C.  The  contraction  at  C  is  caused  by  a  col- 
lision at  C ;  and  the  discharge  from  d  to  C  cannot  take  place 
until  after  the  contraction  at  C  has  commenced.  Neverthe- 
less, though  not  a  nervous  action  proper,  it  may,  by  frequent 
repetition,  grow  into  one.  If  restorations  of  equilibrium  be- 
tween d  and  C  recur  often — if  they  continually  take  the 
same  route  through  the  network  of  protoplasm — if  this 
becomes  a  line  of  less  and  less  resistance  that  drafts  off  the 
molecular  motion  with  rapidity;  then,  eventually,  when  an 
approaching  body  touches  the  end  of  the  tentacle  D,  the  im- 
pulse conveyed  down  it  and  along  the  incipient  nerve  from 
d  to  C  will  reach  C  before  the  approaching  body  touches  it. 
Now  the  contractile  colloid  at  C  is  capable  of  having  its 
special  molecular  transformation  set  up  by  various  stimuli — 
by  communicated  molecular  motion  as  well  as  by  a  blow. 
Hence  when  a  wave  of  disturbance  reaches  it  before  it  re- 
ceives a  blow,  it  will  begin  to  contract  in  anticipation  of  the 
blow.  A  rude  touch  at  the  end  of  the  tentacle  D,  will,  by 
the  shrinking  it  sets  up  at  C,  cause  withdrawal  of  the  body 
from  the  source  of  danger. 

§  228.  To  avoid  complications  of  statement,  I  have  pre- 
sented this  primitive  nervous  action  under  a  simpler  form 
than  that  which  actually  occurs.  For  the  wave  of  molecular 
motion  has  to  be  conveyed  not  to  a  single  point  but  to  a 
portion  of  contractile  colloid  having  considerable  extension, 
many  parts  of  which  simultaneously  become  places  where 
molecular  motion  is  being  absorbed.  Hence  the  wave  pass- 
ing to  it  will  somewhere  on  its  way  tend  to  divide  according 
to  the  respective  tensions  towards  these  respective  parts. 
What  will  result? 

Fig.  6  represents  the  same  general  distribution  as  before, 


THE  GENESIS  OF  SIMPLE  NERVOUS  SYSTEMS.     525 

with  the  difference  that  the  mass  of  contractile  colloid  C,  is 
marked  in  dotted  lines,  and  that  at  e  the  line  of  nervous  com- 
munication is  shown  to  take  divergent 
and  re-divergent  courses  towards  differ- 
ent parts  of  C.  For  this  is  the  structure 
implied.  The  same  tendency  towards  re- 
storation of  equilibrium  which  causes  the 
wave  to  go  from  d  to  C,  will  also  cause 
it  to  distribute  itself  with  tolerable  even- 
ness to  all  parts  of  C;  since  to  any  part 
which  by  contracting  becomes  minus 
molecular  motion,  the  adjacent  parts  must  ever  tend  to  yield 
some  of  their  relative  surplus,  and  this  must  find  its  way 
along  some  line  of  least  resistance. 

Let  us  now  ask  what  will  happen  at  the  place  e.  As  was 
shown  in  the  last  chapter,  the  formation  of  a  nerve-thread 
capable  of  conveying  with  facility  a  wave  of  molecular 
motion,  implies  a  definite  line  pursued  by  the  wave  and  a 
definite  adjustment  of  the  molecules  to  that  line;  and, 
consequently,  such  adjustment  of  the  molecules  as  serves 
for  a  wave  in  one  direction  will  not  serve  for  waves  in 
other  directions.  At  the  place  e,  then,  where  the  wave 
breaks  up  and  its  parts  diverge,  the  molecules  cannot  so  ar- 
range themselves  as  to  conduct  with  facility  all  parts  of  the 
wave.  Recurring  to  our  old  simile,  if  a  regularly-arranged 
line  of  bricks  on  end  comes  to  a  place  where  there  is  a 
cluster  of  bricks  on  end,  from  which  diverge  other  lines  of 
regularly-arranged  bricks  on  end,  it  is  clear  that  when  the 
first  line  is  overthrown  at  its  beginning  and  delivers  its  im- 
pulse into  the  cluster,  the  bricks  forming  the  cluster  must 
be  irregularly  overthrown — cannot  fall  in  the  same  direc- 
tions with  all  the  divergent  lines ;  and  no  repetitions  of  the 
process  can  adjust  the  bricks  of  the  cluster  into  attitudes 
that  will  do  this.  Hence  at  the  point  e  there  will  remain 
some  of  the  nerve-colloid  in  an  amorphous  state.  Though 
between  the  incoming  line  and  the  chief  outgoing  line  (if 


526  PHYSICAL  SYNTHESIS. 

one  carries  much  more  of  the  wave  than  the  rest)  there  may 
at  last  arise  a  polar  arrangement  of  the  molecules,  yet  this 
cannot  also  happen  with  the  minor  outgoing  lines.  But  if 
at  e  the  molecules  remain  unarranged,  the  wave  of  molecular 
motion  brought  there  will  be  checked ;  and  by  as  much  as  it 
is  checked  will  tend  to  cause  decompositions  among  the  un- 
arranged  molecules.  As  when  bricks  placed  askew  fall 
against  one  another,  their  angles  are  more  liable  to  damage 
than  the  angles  of  bricks  placed  symmetrically;  so  a  non- 
polar  arrangement  of  the  molecules  subjects  them  to  destroy- 
ing forces  which  they  are  saved  from  by  a  polar  arrange- 
ment. Now  if  decomposition  occurs  at  e,  additional  mole- 
cular motion  must  be  disengaged;  so  that  along  the 
outgoing  lines  there  will  be  discharged  an  augmented  wave. 
Thus  there  will  arise  at  e  something  having  the  character  of 
a  ganglion-corpuscle. 

That  the  structure  represented  is  like  no  known  struc- 
ture, is  true.  The  most  conspicuous  deviation  from  fact  is 
in  the  wide  spreading  of  the  lines  between  e  and  C.  And  it 
may  be  asked — How  does  their  divergence,  which  appears 
a  necessity  of  the  argument,  become  so  modified  as  to  corre- 
spond with  the  observed  distribution?  I  reply  that  though 
the  process  of  direct  equilibration  will  not  change  this  dis- 
tribution in  the  required  way,  it  can  be  so  changed  by  the 
process  of  indirect  equilibration.  {Principles  of  Biology 
§  164.)  When  in  the  course  of  further  evolution  neighbour- 
ing parts  acquire  distinct  structures,  fibres  occupying  so 
much  space  as  those  between  e,  and  C  will  be  in  the  way. 
An  individual  in  which  the  lines  as  they  leave  the  point  e  do 
not  diverge  so  widely,  will  therefore  have  an  advantage. 
And  gradually,  by  survival  of  the  fittest,  there  will  result  a 
type  that  has  these  once  divergent  fibres  concentrated  into  a 
bundle,  the  members  of  which  part  company  only  when  they 
arrive  at  C. 

A  more  serious  objection  may  be  raised.     The  processes 
given  off  by  ganglion-cells  do  not  ordinarily  continue  on- 


THE  GENESIS  OP  SIMPLE  NERVOUS  SYSTEMS.     527 

wards  as  fibres  that  end  in  muscles,  in  the  way  implied.  The 
hypothesis  as  above  sketched  out,  is  at  variance  with  the 
drawings  of  the  biologist.  But  this  seemingly  fatal  objec- 
tion may,  I  think,  be  satisfactorily  met. 

§  229.  For  there  remains  to  be  introduced  a  complication 
which  I  have,  for  simplicity  sake,  omitted;  and  this  com- 
plication implies  a  structure  that  corresponds  with  fact. 

Throughout  the  exposition  we  have  attended  only  to  the 
effects  caused  by  the  recurring  excitations  of  a  single  ten- 
tacle; and  the  nervous  structure  described  could  arise  only 
in  a  case  of  this  imaginary  simplicity.  In  reality  the  excita- 
tions are  received  by  many  tentacles,  each  of  which  sends  a 
wave  of  disturbance  to  all  parts  of  the  contractile  mass  C.  It 
does  not  follow  that  for  every  tentacle  there  must  be  formed 
an  independent  set  of  nervous  connexions  like  that  shown 
above.  Though  each  afferent  fibre  will  need  some  place 
of  divergence  e,  yet  from  each  such  place  of  divergence, 
it  is  not  needful  to  have  a  separate  nerve-fibre  to  each  of 
the  separate  parts  of  C  that  have  to  contract  simultaneously. 
On  the  contrary,  it  is  inferable  that  as  for  each  afferent  fibre 
there  will  be  some  place  of  divergence  e,  whence  its  wave  of 
molecular  motion  begins  to  distribute  itself;  so,  for  each 
efferent  fibre  communicating  with  each  part  of  C,  there  will 
be  an  analogous  place  of  convergence,  where  all  the  por- 
tions of  waves  going  to  that  part  will  unite.  That  the 
nature  of  the  required  structures  may  be  clearly  concei- 
^  ved,  let  us  first  illus- 

trate,       diagrammati- 
cally,  the  needfiil  con- 
nexions. In 
Fig. 7,  let  A  stand  for 
half  a  dozen   afferent 
fibres,  while  the  dots  at  a  stand  for  the  points  of  divergence 
that  arise  as  above  explained.     Then  if,  in  the  muscle  to 
which  the  wave  is  distributed,  there  are  half  a  dozen  contrac- 
35 


-«*'.  / 


528  PHYSICAL  SYNTHESIS. 

tile  parts  to  be  independently  supplied,  it  is  manifest  that 
instead  of  an  independent  fibre  diverging  from  each  of  the 
points  a,  and  running  to  each  of  the^e  half-dozen  con- 
tractile parts,  the  same  end  will  be  achieved  if  there  are 
half  a  dozen  efferent  fibres  E,  setting  out  from  so  many 
points  e,  which  severally  receive  fibres  from  all  the  points 
a.  Such  an  arrangement  will  indeed  be  more  efficient; 
since  along  a  fibre  which  conveys  a  larger  wave,  composed 
of  many  smaller  waves,  there  will  arise  a  greater  facility  for 
transmission  than  would  arise  along  fibres  that  conveyed 
the  smaller  waves  separately.  A  still  simpler  system 

of  connexions  will  serve  equally  well,  or — for  reasons  like 

those  just  assigned — 
still  better.  To  bring 
any  one  of  the  points 
a  into  connexion  with 
all  the  points  «,  there 
does  not  need  a  sepa- 
rate fibre  all  the  way 
to  each.  The  arrange- 
ment shown  in  Fig.  8, 
or  that  shown  in 
"^^  Fig.     9,    will    suffice, 

l^or  must  even  this  more  integrated  set  of  connexions  be 
repeated  in  full  for  each  of  the  points  a.    In  Fig.  10,  each 

point  a  is  joined  with 
every  point  e,  by  a 
much  smaller  number 
of  fibres.  And  since 
j^^a   ^^,  lY^Q  fibres  in  this  sys- 

tem will  be  more  used  than  those  in  any  other  system,  they 
will  become  more  permeable  channels. 

Will  this  kind  of  structure  result  from  the  convergence 
and  divergence  of  waves  of  molecular  motion  following 
lines  of  least  resistance?  We  may  infer  that  it  will.  If 
to  some  point  a  in  Fig.  9,  there  has  been  brought  by  the 


THE  GENESIS  OF  SIMPLE  NERVOUS  SYSTEMS.     529 

afferent  fibre  from  a  tentacle  a  wave  of  molecular  motion; 
if  all  the  points  e  are  the  beginnings  of  efferent  fibres 
severally  ending  in  separate  portions  of  a  contractile  mass, 
which  by  contracting  has  just  become  a  place  where  mole- 
cular motion  is  absorbed;  if,  therefore,  between  this  point 
a  and  all  the  points  e,  there  arise  molecular  tensions;  then 
the  restoration  of  equilibrium  will  be  effected  by  waves  of 
molecular  motion  which,  following  a  common  route  for  some 
distance,  will  break  up  and  diverge  on  approaching  the 
points  e — the  numbers  and  positions  of  the  places  of  di- 
vergence being  determined  by  local  conditions.  Further, 
if  from  another  of  the  points  a,  a  wave  has  similarly  to 
find  its  way  along  lines  of  least  resistance  to  all  the  points 
e,  it  will  do  so  by  passing  into  some  near  point  of  this 
same  plexus.  So  that  between  all  the  points  a  and  all 
the  points  e,  there  will  be  produced  numerous  places  of 
converging  and  diverging  communication;  each  of  which, 
for  reasons  above  assigned,  will  be  a  place  containing  un- 
arranged  and  unstable  molecules  of  nerve-matter,  liable  to 
be  decomposed  when  disturbed,  and  to  pass  on  in  increased 
amounts  the  waves  that  disturb  them. 

Now  if  instead  of  the  regularly  arranged  lines  and 
points,  we  conceive  lines  and  points  irregularly  arranged; 
and  if  instead  of  the  half-dozen  afferent  fibres  and  as  many 
efferent  fibres,  we  suppose  a  score  or  more  of  each  (which 
we  must  do  to  correspond  with  even  the  simplest  observ- 
able cases);  and  if  we  proportionately  complicate  the  con- 
necting plexus;  we  shall  have  something  like  a  ganglion. 
Fig.  11  represents  such  a  structure.  That  it  is  less  intri- 
cate than  an  actual  gang- 
lion is  what  might  be  ex- 
pected. The  conditions 
^^  >^^^^^  presented  by  a  mass  of 

protoplasm  out  of  which  a  ganglion  is  evolved,  are  sure 
to  cause  great  irregularities;  and  it  is  not  difficult  to  see 
that  in  the  course  of  its  evolution,  there  are  likely  to  arise 


530  PHYSICAL  SYNTHESIS. 

many  incipient  lines  of  connexion  which  do  not  develop 
further  because  others  have  superseded  them.  The  agree- 
ment between  inference  and  observation  is,  I  think,  as 
close  as  we  can  reasonably  look  for. 

It  may,  indeed,  be  objected  that  an  actual  ganglion  differs 
from  this  hypothetical  ganglion  in  a  more  serious  way — in 
not  displaying  a  definite  network.  The  microscope  dis- 
closes an  entangled  maze  of  fibres,  cells,  and  branched  pro- 
cesses, that  are  not  formed  into  a  distinct  plexus  of  con- 
nexions. To  this  my  reply  is,  that  though  I  have  thus  far, 
for  the  sake  of  clearness,  spoken  of  these  structures  as 
definite,  it  is  not  needful  that  they  should  be  visibly  so.  A 
network  of  lines  of  least  resistance,  is  alone  requisite ;  and  it 
may  be  in  part  so  formed  as  to  be  visible  and  in  part  so  un- 
formed as  to  be  invisible.  This  qualification  must  be  borne 
in  mind  as  applying  throughout  the  chapters  that  are  to 
follow. 

§  230.  Let  me  before  closing  dispose  of  a  remaining 
objection.  A  critical  reader  may  ask — How  can  a  state  of 
molecular  tension  between  two  places  separated  by  a  great 
mass  of  amorphous  organic  substance,  cause  transmission 
along  a  definite  line  that  divides  and  sub-divides  in  the  way 
described  ? 

Doubtless  such  a  process  is  not  easy  to  imagine  under  the 
conditions  we  are  apt  to  assume.  But  the  apparent  difficulty 
disappears  when,  instead  of  the  conditions  we  are  apt  to 
assume,  we  take  the  conditions  which  actually  occur.  The 
error  naturally  fallen  into  is  that  of  supposing  these  actions 
to  go  on  in  creatures  of  considerable  bulk ;  whereas  observa- 
tion warrants  us  in  concluding  that  they  go  on  in  extremely 
small  creatures.  The  type  of  nervous  system  approaching 
nearest  in  simplicity  to  the  hypothetical  one  described,  we 
find  among  the  Pobyzoa — creatures  of  almost  microscopic 
minuteness.  The  total  length  of  an  individual  Polyzoon  is 
from  a  40th  to  a  20th  of  an  inch;   and  if  we  set  down  the 


THE  GENESIS   OF  SIMPLE  NERVOUS  SYSTEMS.     531 

distance  from  the  roots  of  the  tentacles  to  the  nearest  point 
of  the  muscle  at  a  100th  of  an  inch,  we  shall  be  much  beyond 
the  mark.  When  the  scale  is  thus  immensely  reduced,  the 
physical  processes  described  become  comprehensible.  The 
thickness  of  protoplasm  through  which  these  restorations  of 
equilibrium  are  effected  being  recognized  as  about  the 
thickness  of  stout  paper,  it  is  no  longer  difficult  to  con- 
ceive the  molecular  tensions,  and  transmissions  of  mole- 
cular motion,  to  take  place  in  the  way  alleged,  with  the 
inferred  results. 

The  structure  described  having  been  first  formed  on 
this  extremely  small  scale,  admits  of  eventual  enlargement 
to  any  scale.  Conducing  to  the  preservation  and  growth 
of  the  individual;  inherited  by  progeny  capable  from 
the  aid  it  yields  of  growing  still  larger;  and  bequeathed 
with  its  accumulated  increments  of  size  and  development  to 
successively  higher  types,  that  spread  into  better  habitats 
and  adopt  more  profitable  modes  of  life ;  this  mere  rudiment 
may,  in  course  of  geologic  epochs,  evolve  into  a  conspicuous 
nervous  apparatus  possessed  by  a  creature  of  large  size. 
And  so  by  this  slow  indirect  method  there  may  be  estab- 
lished lines  of  nervous  communication  where  direct  estab- 
lishment of  them  would  be  impossible. 

Finally,  it  may  be  well  to  remind  the  reader  that  the 
argument  does  not  necessitate  the  assertion  that  the  primi- 
tive nervous  system  was  formed  in  this  particular  way.  The 
essence  of  the  argument  is,  that  to  some  place  of  greatest 
and  most  frequent  contraction,  lines  of  discharge  will  be 
formed  from  places  habitually  touched  before  this  contrac- 
tion is  set  up ;  and  the  case  I  have  chosen  is  one  which  lent 
itself  most  readily  for  explanation — not  one  therefore  as- 
serted to  be  actual.  With  this  caveat  let  us  now  pass  from 
the  simplest  case  to  more  complex  cases. 


CHAPTER  IV. 

THE   GENESIS    OF   COMPOUND    NEEVOUS   SYSTEMS. 

§  231.  When  contemplating  the  incipient  differentiation 
of  the  psychical  life  from  the  physical  life  (§  140),  it  was 
pointed  out  that  the  special  senses  arise  through  local 
modifications  of  nutrition  caused  by  the  special  agents  re- 
sponded to.  In  some  of  the  lowest  animals  the  semi- 
transparent  body  is  coloured  green,  red,  or  brown,  by 
scattered  portions  of  a  matter  akin  to  the  colouring  matter 
of  plants;  and  the  sensitiveness  of  these  creatures  to  light  is 
doubtless  due  to  the  assimilative  actions  which  light  sets  up 
in  this  matter.  Higher  animals  also  habitually  contain 
pigment,  in  cells  and  scattered  granules;  and  though  these 
are  not  limited  to  the  superficial  tissue,  they  are  ordinarily 
most  abundant  in  it.  Of  course  the  nutrition  of  deep- 
seated  portions  of  pigment  goes  on  in  the  absence  of  light. 
But  though  light  is  certainly  not  the  only  cause  of  the 
nutrition  of  pigment,  and  perhaps  not  the  chief  cause,  there 
is  evidence  that  it  is  a  cause;  since  pigment-grains  near 
the  surface  commonly  increase  in  size  or  number  or  both 
when  much  exposed  to  light.  At  any  rate,  we  may  safely 
say  that  in  some  kinds  of  pigment  produced  in  animal  tissue, 
light  produces  marked  molecular  changes. 

Now  the  rudimentary  eye  consists  of  a  few  pigment- 
grains  under  the  outermost  dermal  layer;  and  hence 
we  may  infer  that  rudimentary  vision  is  constituted  by 
the  wave  of  disturbance  which  a  sudden  change  in  the 

states  of  these  pigment-grains  propagates  through  the  body. 

533 


THE  GENESIS  OP  COMPOUND  NERVOUS  SYSTEMS.  533 

How  such  pigment-grains  become  concentrated  in  the  parti- 
cular places  they  may  most  advantageously  occupy  we  need 
not  consider  at  any  length.  Other  things  equal,  they  will 
develop  most  where  most  light  falls,  and  where,  consequently, 
variations  of  light  caused  by  adjacent  things  are  strongest; 
and  since  a  close  cluster  of  pigment-grains  when  affected,  will 
send  through  the  body  a  more  efficient  wave  of  disturbance, 
natural  selection  will  further  the  concentration — there  will 
be  a  survival  of  individuals  in  which  the  approximation  is 
greatest,  ending  in  the  formation  of  an  integrated  patch. 

The  pre-existence  of  a  simple  nervous  system,  akin  to 
that  described  in  the  last  chapter,  being  assumed,  let  us 
consider  what  will  happen  when  incipient  vision  is  added. 

§  232.  Suppose  f.  Fig.  12,  to  be  the  cluster  of  pigment- 
grains  constituting  the  rudimentary  eye.  And  suppose  that 
from  these  pigment-grains,  when  changed  ly  variations  in 
the  amounts  of  light  falling  on  them,  there  have  been  pro- 
pagated waves  of  disturbance  into  the  mass  of  organism. 
Then  wherever  these  waves  eventually  go,  there  will  arise 
j^^^  behind  these  pigment-grains  at  g,  a  plexus 
of  fibres  and  ganglion-cells.  For  reasons 
such  as  were  given  in  §  229  the  separate 
waves  setting  out  from  the  separate  dis- 
turbed pigment-grains,  and  pursuing  lines 
of  least  resistance,  will  quickly  unite ;  and 
there  will  result  a  cluster  of  junctions 
occupied  by  unstable  nerve-matter,  whence 
the  aggregate  wave  will  direct  itself  in- 
wards. 

To  what  place  will  it  tend?  As  before,  to  the  place  where 
molecular  motion  is  being  absorbed.  If  immediately  after 
molecular  motion  is  liberated  at  f,  molecular  motion  is 
taken  up  in  the  muscle  C,  a  molecular  tension  will  arise 
between  f  and  C;  and  motion  along  the  line  of  least 
resistance  will  result.      Which  will  be  the  line  of  least 


534  PHYSICAL  SYNTHESIS. 

resistance?  Already  there  has  been  formed  a  line  of  easy 
transmission  from  the  tactual  organs  to  the  muscle,  along 
the  line  ^  to  C;  and,  other  things  equal,  the  line  of  least 
resistance  from  /  to  C  will  be  one  of  which  this  pre-existing 
channel  forms  a  part.  Hence  the  tendency  will  be  for  the 
wave  of  molecular  motion  to  take  its  course  from  /  through 
the  underlying  plexus  g  to  the  pre-established  ganglion  at 
e;  and  gradually  to  form  a  connecting  fibre. 

What  will  be  the  functional  effects  of  this?  So  long  as 
the  nervous  communication  is  incipient,  contraction  must  be 
set  up  in  the  muscle  C,  hefore  molecular  motion  disengaged 
at  /  can  cause  a  state  of  tension  between  /  and  C,  and 
therefore  an  impression  on  the  rudimentary  eye  will  not 
produce  a  contraction.  The  only  advantage  derivable  from 
such  a  structure  in  this  early  stage,  would  seem  to  be  that 
of  increasing  the  amount  of  contraction  otherwise  initiated. 
But  as  soon  as  the  channel  for  the  transmission  of  molecular 
motion  from  /  to  the  ganglion  e  becomes  tolerably  perme- 
able, the  molecular  motion  disengaged  by  an  impression  at  f, 
finding  its  way  along  this  channel,  may  reach  the  muscle 
before  the  molecular  motion  set  up  by  touch  can  reach  it; 
and  a  consequent  contraction  of  the  muscle  will  withdraw 
the  body  in  anticipation  of  touch — the  creature  will  retreat 
as  though  alarmed  by  the  approaching  object. 

§  233.  A  nervous  system  of  the  type  described  in  the  last 
chapter,  or  even  a  nervous  system  a  stage  more  complex  in 
type,  like  that  just  described,  can  effect  none  but  the 
simplest  adjustments.  Small  extensions  of  the  correspond- 
ence in  Space  and  in  Time  are  alone  achievable  by  it. 
Muscular  contraction  is  produced  by  a  certain  strength  of 
impression  on  the  tentacles,  whatever  be  the  nature  of  the 
body  striking  them  or  the  direction  in  which  it  is  moving. 
Similarly,  the  rudimentary  eye  can  do  no  more  than  convey 
to  the  muscle  the  impression  caused  by  a  change  in  the 
quantity  of  incident  light;   no  matter  whether  that  change 


THE  GENESIS  OF  COMPOUND  NERVOUS  SYSTEMS.  535 


be  caused  by  a  small  body  close  to  or  by  a  large  one  far  off, 
and  no  matter  whether  the  motion  of  the  body  is  or  is  not 
such  as  will  presently  cpuse  a  collision.  liervous  systems 
of  these  kinds  can  bring  about  no  special  adjustments  of  the 
inner  acts  to  special  directions  and  distances  of  outer  objects. 
Let  us  consider  what  further  complications  will  initiate  such 
further  adjustments. 

More  muscles  than  one  are  obviously  pre-supposed;  other- 
wise the  motion  can  vary  in  amount  only.  And  there  are 
obviously  pre-supposed  more  than  one  place  of  independent 
stimulation ;  otherwise  not  more  than  one  kind  of  impulse 
to  contraction  can  be  given.  If  all  the  tentacles  are  simi- 
larly connected  with  the  same  muscle,  or  if  the  channel  of 
communication  which  each  pigment-grain  in  the  eye-speck 
has  with  the  muscle  is  like  that  which  every  other  has,  there 
can  be  no  qualitative  distinctions  among  stimuli,  and  there- 
fore no  specialized  motions.  A  simple  locomotive  creature 
(moved  of  course  by  muscles  and  not  by  cilia)  fulfils  the 
requisite  conditions.  Let  us  suppose  one  that  is,  like  most 
locomotive  creatures,  bilaterally  symmetrical — one  having 
mJ3  two  rudimentary  eyes  and  the  two  muscles,  or 
sets  of  muscles,  which  the  locomotion  of  such 
creatures  implies.  Suppose  that  in  Fig.  13,  a 
and  &  are  the  nerve-threads  coming  from  the 
two  rudimentary  eyes  to  the  ganglion  e;  and 
that  through  this,  each  of  these  threads  is  con- 
nected with  all  the  threads  in  each  of  the  two 
bundles  d  and  /,  running  to  the  muscles  G  and 
H.  Setting  out  with  the  least  differentiated 
structure,  we  will  assume  that  by  means  of  the 
plexus  at  6,  each  afferent  fibre  is  similarly  con- 
nected, and  equally  well  connected,  with  each 
bundle  of  efferent  fibres.  What  will  in  such  case 
happen?  The  stimuli  continually  received 
through  the  eye-specks  as  the  creature  moves  through  the 
water^  will  act  indifferently,  and  equally,  through  the  two 


536  PHYSICAL  SYNTHESIS. 

motor  bundles  on  the  two  sets  of  muscles — the  alternating 
contractions  of  these  supplying  an  instance  of  the  rhythm  in- 
evitably generated  by  antagonistic  energies.  Only  one  spe- 
cialization of  the  movements  will  be  effected.  So  long  as  the 
changes  in  the  visual  stimuli  arising  from  objects  which  the 
creature  passes,  or  which  pass  it,  are  moderate,  the  muscles 
will  be  excited  to  moderate  contractions.  But  the  approach 
of  a  large  object,  causing  sudden  and  strong  impressions  on 
the  rudimentary  eyes,  will  send  to  the  muscles  sudden  and 
strong  discharges,  making  them  violently  contract  so  as  to 
produce  a  dart — a  dart  which,  though  made  at  random,  will 
usually  decrease  the  chance  of  being  caught,  if  the  approach- 
ing body  is  a  predatory  animal.  But  now,  however  much 
alike  the  connexions  of  the  two  afferent  fibres  with  the  two 
bundles  of  efferent  fibres  may  have  originally  been,  it  must 
happen  in  virtue  of  the  universal  law  of  the  instability  of  the 
homogeneous,  that  they  will  become  in  some,  or  rather  in 
most,  individuals  of  the  species,  slightly  unequal.  Let  the 
cells,  processes  and  fibres  of  the  ganglion  e,  be  congenitally 
developed  in  such  ways  that  the  fibre  a  has  somewhat  easier 
communication  with  the  bundle  d  than  with  the  bundle  f,  or 
vice  versa  /  and  let  the  connexions  of  the  fibre  &  similarly 
deviate  from  complete  equality.  The  effects  on  ordinary 
locomotion  and  on  the  motion  of  escape  just  described,  will 
be  insignificant;  but  there  will  occur  under  certain  circum- 
stances modified  motions  of  great  significance.  Suppose  that 
on  the  side  A,  an  adjacent  small  object  produces  in  the  eye- 
speck,  and  sends  through  the  optic  fibre,  a  moderate  disturb- 
ance. If  the  connexions  of  this  fibre  vtdth  the  efferent  bundle 
f  are  better  than  its  connexions  with  the  efferent  bundle  d, 
the  muscle  on  the  opposite  side  of  the  body  will  contract 
most ;  and  the  body  (supposing  it  to  bend  like  that  of  a  fish) 
will  be  turned  moa/y  from  the  object  which  produced  the  im- 
pression. If,  contrariwise,  its  connexions  with  the  bundle 
on  its  own  side  are  the  best,  the  body  will  be  turned  towards 
the  object.    Now  in  many  cases  the  object  is  one  that  will 


THE  GENESIS  OP  COMPOUND  NERVOUS  SYSTEMS.  537 

serve  for  food.  If,  then,  this  congenital  variation  in  the 
nervous  connexions  is  such  that  a  moderate  stimulus  on  the 
eye-speck  makes  the  body  turn  away  from  the  object  yield- 
ing the  stimulus,  the  individual  will  lose  rather  than  gain  by 
the  incipient  vision;  and  will  therefore  disappear.  A  con- 
trary variation  of  structure,  entailing  a  contrary  effect,  will 
conduce  to  the  welfare  of  the  individual  on  every  occasion 
when  the  object  towards  which  the  body  is  turned  is  food. 
Each  discharge  thus  sent  in  excess  towards  the  one  set  of 
muscles,  will  increase  the  relative  permeability  of  the  one  set 
of  channels  over  the  other;  making  the  one-sidedness  of  the 
next  discharge  greater  still.  And  since  the  more  decided 
this  tendency  becomes  the  more  decidedly  the  welfare  of  the 
individual  will  be  furthered,  the  creature's  life  will,  on  the 
average  of  cases,  be  longer,  and  the  number  of  progeny  left 
will  be  greater  than  is  usual  in  the  species.  I  need  scarcely 
add  that  among  descendants  inheriting  this  modification, 
functionally  increased  during  the  entire  life  of  the  parent, 
the  same  causes  will  insure  not  simply  continuance  of  it  but 
progressive  development. 

§  234.  A  further  step  may  now  be  taken.  The  ad- 
vantages derivable  from  rudimentary  eyes  such  as  are 
above  supposed,  will  increase  as  the  eyes  are  evolved, 
whether  in  size  or  in  structure.  A  larger  sensitive  area 
will,  other  things  equal,  render  the  creature  impressible  by 
smaller  objects  and  by  remoter  objects,  thereby  conducing 
to  its  welfare ;  so  that  survival  of  the  fittest  will  favour  the 
growth  of  visual  spots  made  up  of  numerous  sensitive  ele- 
ments. As  this  multiplication  of  sensitive  elements  pro- 
gresses the  ganglionic  plexus  underneath  the  eye-speck  will 
develop,  and  there  will  fall  an  additional  amount  of  function 
on  the  fibres  connecting  it  with  the  central  ganglion.  This 
increase  of  function  may  entail  either  increased  thickness 
of  these  fibers  or  increased  number  of  them.  The  one 
will  arise  from  inheritance  of  functionally-produced  modi- 
fications.    The  other  will  arise  from  inheritance  of  in- 


538  PHYSICAL  SYNTHESIS. 

cidental  variations;  since  we  have  clear  proof  that  in  a 
cluster  of  homologous  parts  there  occasionally  arises  a  mem- 
ber in  excess  of  the  normal  number.  Assuming  that  a 
bundle  of  nerve-fibres  connecting  the  enlarged  eye  with  the 
central  ganglion  has  been  thus  established,  let  us  ask  what 
will  happen.  From  the  instability  of  the  homogeneous  it 
follows,  as  before,  that  however  completely  alike  may  at  first 
have  been  the  connexions  of  these  fibres  with  the  different 
parts  of  the  central  ganglion,  their  connexions  cannot  re- 
main alike.  And,  as  before,  it  is  clear  that  while  some 
variations  in  their  connexions  will  affect  the  movements 
of  the  creature  favourably  others  will  affect  them  unfa- 
vourably. What  are  the  favourable  variations 
likely  to  be?  If  over  the  visual  surface,  now  composed  of  a 
considerable  number  of  sensitive  elements,  the  transparent 
epidermis  has,  by  survival  of  the  fittest,  acquired  that  con- 
vexity usually  observable,  the  impressions  received  will  fall 
on  the  whole  patch  of  sensitive  elements  only  when  the 
objects  producing  them  are  opposite  to  the  patch — an  object 
much  in  advance  or  behind,  much  above  or  below,  will  cast 
a  vague  image  on  one  portion  of  the  patch  only.  Hence  if 
the  fibres  composing  the  afferent  bundle  are  not  related  with 
absolute  equality  to  all  parts  of  the  nervous  plexus  under- 
lying the  patch  of  sensitive  elements  (and  mere  differences 
of  position  must  entail  inequality)  it  will  happen  that  when, 
out  of  the  patch  of  sensitive  elements,  one  group  is  affected 
more  than  the  rest,  some  members  of  the  afferent  bundle 
will  carry  larger  waves  of  molecular  disturbance  than  the 
rest.  In  cases  where  the  muscular  system  consists,  as  sup- 
posed in  the  last  section,  of  but  two  contractile  masses 
capable  of  acting  only  as  wholes,  this  somewhat  increased 
heterogeneity  of  the  recipio-motor  structures  will  produce 
no  definite  effects.  But  it  is  an  inductively-established  fact 
that  there  frequently  occur  variations  in  the  numbers  and 
attachments  of  muscular  bundles :  even  in  so  specific  a  type 
as  the  human,  such  variations  are  not  uncommon.    Suppos- 


THE  GENESIS  OF  COMPOUND  NERVOUS  SYSTEMS.  539 

ing,  then,  the  muscles  have  here  been  modified  some- 
what in  the  direction  of  multiformity,  a  further  specializa- 
tion of  movements  becomes  possible.  For  a  discharge 
carried  more  largely  by  some  fibres  of  the  incipient  optic 
nerve  than  by  others,  will,  on  arriving  at  the  central 
ganglion,  diffuse  itself  not  quite  in  the  same  way  as  one 
brought  by  all  the  fibres  in  equal  amounts.  Hence  two 
somewhat  different  discharges  taking  somewhat  unlike 
courses  through  the  central  plexus  of  fibres  and  cells,  and  is- 
suing in  their  multiplied  amounts  through  a  bundle  of  effer- 
ent fibres,  will  severally  affect  this  in  diverse  ways — some 
fibres  of  the  bundle  taking  more  of  the  one  discharge  and 
some  more  of  the  other.  So  that  if  the  masses  of  contractile 
substance  to  which  this  bundle  of  efferent  fibres  is  distributed 
are  capable  of  any  separateness  in  their. actions,  the  two  dis- 
charges will  work  on  them  unlike  effects,  and  the  motions 
produced  will  not  be  the  same.  Now  the  differences  in  the 
produced  motions,  relatively  to  the  objects  causing  these 
special  impressions,  are  almost  certain  to  be  advantageous  or 
disadvantageous.  And,  as  before,  the  structures  producing 
motions  that  are  on  the  average  advantageous  will  conduce 
to  the  long  life  of  the  individual ;  will  be  developed  by  their 
repeated  actions  during  this  long  life;  and  will  be  be- 
queathed with  some  functionally-produced  improvements 
to  posterity. 

§  235.  It  is  not,  I  think,  difficult  to  see  that  the  same 
principles  continue  to  hold;  and  that  through  successive 
small  stages  of  analogous  kinds,  nervous  systems  may  go 
on  complicating.  Let  us  glance  at  the  processes  that  are 
likely  to  occur  in  a  central  ganglion  that  receives  and  sends 
out  many  compound  bundles  of  nerve-fibres. 

As  implied  by  what  has  been  said  above,  when  com- 
pound afferent  bundles  become  channels  of  communication 
from  sense-organs  severally  composed  of  many  separate 
elements,  the  discharges  they  carry  into  the  central  gang- 


540  PHYSICAL  SYNTHESIS. 

lion  become  very  variable  in  composition,  and  diffuse  them- 
selves through  its  plexus  in  waves  that  are  never  twice 
exactly  alike.  The  fibres  composing  the  optic  nerve,  for  ] 
example,  receive  different  sets  of  stimulations  according  to  \ 
the  size  of  the  object,  its  form,  its  direction,  its  distance. 
Consequently  after  a  well-established  reflex  connexion  has 
been  formed  between  the  visual  impression  given  by  a 
certain  kind  of  prey  in  a  certain  position,  and  the  muscular 
adjustment  required  to  seize  such  prey,  it  will  happen  that 
the  excitement  of  the  muscles  must  be  preceded  by,  and  ac- 
companied by,  numerous  other  excitements.  For  while  there 
are  going  on  those  relative  motions  that  end  in  bringing  the 
prey  to  the  position  which  calls  forth  the  reflex  action,  many 
changing  sets  of  impressions  are  being  made  on  the  optic 
fibres — some  of  them  conducing  to  the  approaching  reflex 
action  and  some  of  them  conducing  to  other  actions. 
Hence  in  the  central  ganglion,  numbers  of  fibres  and 
cells  become  nascently  excited  before  a  certain  group  of 
them  become  excited  in  such  way  as  to  cause  the  appro- 
priate discharge  to  the  muscles.  Now  the  nascent  excita- 
tions so  caused  are  not  lost:  they  nascently  excite  multi- 
tudinous efferent  fibres  belonging  to  various  bundles;  and 
through  them  throw  various  muscles  into  states  of  partial 
tension.  Here,  then,  is  an  ever-present  opportunity  for 
further  specialization  of  the  correspondence.  Suppose,  for 
instance,  that  the  reflex  action  above  described  is  well 
adjusted  to  catching  a  special  object  seen  in  a  special 
position,  but  that  no  means  exists  of  so  modifying  the 
reflex  action  as  to  allow  for  the  motion  which  the  object 
has  when  it  reaches  this  position.  What  will  happen?  I 
As  the  object  approaches  this  position  from  different  direc- 
tions, its  image  will  travel  over  different  sets  of  retinal  :i 
elements.  In  passing  over  any  particular  set  it  excites  in  ] 
succession  certain  groups  of  optic  fibres,  certain  clusters  of 
fibres  and  cells  in  the  central  ganglion,  and  through  them 
nascently  excites  many  efferent  fibres  with  the  muscles  they 


THE  GENESIS  OF  COMPOUND  NERVOUS  SYSTEMS.  541 

supply.  The  motions  that  will  be  gone  through  when  the 
reflex  action  takes  place,  are  sure  to  be  somewhat  modified 
by  these  states  of  tension  previously  given  to  muscles  not 
immediately  concerned.  The  modification  may  or  may  not 
tend  to  compensate  for  the  motion  which  the  object  had 
when  it  reached  the  point  where  reflex  action  was  set  up. 
But  if,  by  tending  to  compensate  for  this  motion,  the 
modification  is  beneficial,  the  structure  producing  it  will 
be  further  developed ;  and,  as  before,  will  be  established  as 
an  additional  adjustment  of  inner  relations  to  outer  rela- 
tions. 

Before  proceeding  let  us  note,  as  bearing  on  the  inter- 
pretations given  in  preceding  parts  of  this  work,  as  well 
as  on  interpretations  about  to  be  given,  that,  as  above 
understood,  each  of  these  adjustments  of  inner  to  outer 
relations  which  eventually  becomes  automatic,  passes 
through  stages  in  which  it  is  not  automatic.  It  begins 
as  a  slight  tendency  for  an  impression  or  impressions  to 
excite  some  muscle  or  muscles  more  than  the  rest. 
During  this  stage  the  passage  of  the  disturbance  through 
the  chief  nervous  centre  is  slow,  hesitating,  irregular. 
The  sense-impressions  being  an  appreciable  time  in  the 
nervous  centre  before  they  produce  partial  motor  excite- 
ments, remain  present  there  as  sense-impressions;  and  are 
then  the  equivalents  of  what,  in  higher  creatures,  we  call 
sensations.  Similarly,  the  nascent  motor  excitements  are 
the  equivalents  of  what,  in  higher  creatures,  are  the  ideas 
of  the  contractions  to  be  produced.  Gradually  as,  by 
repetition  in  the  individual  and  in  the  succession  of  indi- 
viduals, this  additional  connexion  between  impressions  and 
motions  becomes  more  definite,  and  the  sequence  more 
rapid,  that  link  in  it  which  is  either  consciousness  or  the 
homologue  of  consciousness,  becomes  shorter,  and  the  pro- 
cess passes  into  the  purely  automatic. 


CHAPTER  V. 

THE    GENESIS    OF    DOUBLY-COMPOUND    NEBV0U8    SYSTEMS. 

§  236.  When  instead  of  nerves  of  touch  proceeding  from 
a  dozen  or  a  score  of  tentacles,  we  have  to  deal  with  multi- 
tudes of  such  nerves  proceeding  from  all  parts  of  the  skin — 
when  instead  of  a  simple  eye,  or  an  eye  containing  but  few 
retinal  elements,  we  take  an  eye  having  a  retina  made  up  of 
thousands  of  elements,  each  of  which  yields  a  separate  im- 
pression— when  bundles  of  afferent  fibres  from  complex 
organs  of  hearing,  taste,  and  smell  have  to  be  taken  into 
account — when  the  stimuli  carried  in  ever-varying  amounts 
and  combinations  through  these  recipio-motor  structures 
have  to  be  traced  in  their  effects  upon  similarly-compounded 
dirigo-motorstrucivire^  explanations  of  the  kind  attempted 
in  the  foregoing  pages  become  very  difficult  if  not  im- 
possible. But  though  we  cannot  hope  to  interpret  speci- 
fically the  higher  complications  of  nervous  development,  we 
may  hope  to  form  some  general  idea  of  the  ways  in  which 
the  processes  traced  thus  far  may  work  out  results  still 
more  involved.  To  facilitate  the  formation  of  such  general 
idea,  it  will  be  well  to  contemplate  afresh  the  characters 
of  the  evolution  we  have  followed  thus  far — changing 
somewhat  the  point  of  view,  re-inforcing  some  of  the  con- 
clusions reached,  and  developing  others  a  stage.  We  shall 
then  be  better  able  to  see  where  further  evolution  along  the 

same  lines  is  likely  to  carry  us. 

543 


GENESIS  OF  DOUBLY-COMPOUND  NERVOUS  SYSTEMS.  543 

§  237.  So  long  as  there  exists  but  a  single  afferent  nerve 
and  a  single  muscle  supplied  by  the  accompanying  efferent 
nerve,  external  stimuli  will  produce  but  one  kind  of  action, 
varying  only  in  degree.  Even  when  the  epi-peripheral  im- 
pressions are  received  at  any  or  all  of  numerous  points,  such 
as  the  ends  of  tentacles,  it  must  still  happen  that  while  the 
motor  apparatus  remains  quite  simple,  no  modifications  in 
the  creature's  adjustments  can  be  made  beyond  the  greater 
or  less  promptness  and  strength  of  the  induced  contractions. 

Such  small  change  as  a  bifurcation  and  double  insertion 
of  the  muscular  bundles,  makes  possible  some  difference  in 
the  kind  of  effect  consequent  on  difference  in  the  kind  of 
stimulation.  And  as  the  nervo-muscular  system  becomes 
more  complex,  it  becomes  possible  for  various  unlike  sets  of 
epi-peripheral  impressions  to  produce  various  unlike  com- 
binations of  muscular  actions. 

But  this  compounding  of  stimuli  results  in  the  appro- 
priate compounding  of  movements,  only  on  condition  that 
the  nervous  centres  have  become  proportionately  com- 
pounded. The  required  compounding  of  them  is  in  prin- 
ciple this: — The  connexions  of  their  fibres  must  be  such 
that  when  any  set  of  external  relations  to  which  the  acts 
are  to  be  adjusted,  has  been  impressed  on  the  senses,  the 
special  cluster  of  stimulations  produced,  being  carried  along 
various  afferent  nerves,  is,  in  the  central  plexus,  so  re- 
distributed that,  in  passing  out  again,  it  discharges  itself 
through  particular  sets  of  motor-fibres  in  particular  pro- 
portions. 

Every  further  re-distribution  of  this  kind  implies  addi- 
tional places  for  convergence  and  divergence  of  the  nerve- 
waves — additional  ganglionic  corpuscles.  If  a  certain  group 
of  incoming  fibres  brings  nerve  waves  bearing  certain 
proportions  to  one  another,  the  appropriate  group  of  out- 
going fibres  cannot  have  its  components  affected  in  the 
requisite  degrees  unless  there  exists  between  the  two  groups 

a  duly  adjusted  set  of  convergent  and  divergent  channels, 
86 


544  PHYSICAL  SYNTHESIS. 

differing  in  part  from  all  other  sets.  A  general  diffusion 
through  the  plexus  could  cause  nothing  but  a  general  mus- 
cular excitement;  and  a  special  diffusion  ending  in  discharges 
that  are  special  in  their  directions  and  quantities  is  impos- 
sible unless  by  the  intermediation  of  a  special  structure  that 
is  definite  in  proportion  as  the  co-ordination  is  definite. 

As  the  case  has  been  thus  far  stated,  there  can  arise  no 
such  more  specialized  or  more  complex  muscular  action 
following  the  appropriate  compound  impression,  unless 
through  some  favourable  variation  in  the  structure  of  the 
ganglionic  plexus.  But  eventually  a  new  cause  of  develop- 
ment comes  into  play.  There  comes  a  stage  at  which  ad- 
justments of  inner  to  outer  relations  may  not  only  be  in- 
directly established  by  the  survival  of  individuals  having 
favourable  variations;  they  may  also  be  directly  established 
by  the  inheritance  of  functionally-produced  changes.  And 
the  direct  establishment  of  them  becomes  active  when  there 
exists  a  consciousness  sufficiently  developed  to  perceive  the 
connexion  between  a  muscular  act  and  its  immediate  effect; 
and  when  the  creature  is  thus  rendered  capable  of  making 
slight  modifications  in  its  acts,  of  establishing  these  modi- 
fications as  habits,  and  of  causing  correlative  modifications 
in  its  nervous  centres. 

Before  this  process  can  be  understood,  it  must  be  pre- 
mised that  as  nervous  structures  become  more  complex 
and  more  integrated,  the  network  of  their  connexions 
becomes  so  close  that  every  special  muscular  excitement 
is  accompanied  by  some  general  muscular  excitement. 
Along  with  the  concentrated  discharge  to  particular 
muscles,  the  ganglionic  plexuses  inevitably  carry  off  a 
certain  diffused  discharge  to  the  muscles  at  large;  and 
this  diffused  discharge  produces  on  them  very  variable 
results.  Suppose,  now,  that  in  putting  out 

its  head  to  seize  prey  scarcely  within  reach,  a  creature 
has  repeatedly  failed.  Suppose  that  along  with  the  group 
of  motor  actions  approximately  adapted  to  seize  prey  at 


GENESIS  OF  DOUBLY-COMPOUND  NERVOUS  SYSTEMS.  545 

this  distance,  the  diifused  discharge  is,  on  some  occasion, 
so  distributed  throughout  the  muscular  system  as  to  cause 
a  slight  forward  movement  of  the  body.  Success  will 
occur  instead  of  failure;  and  after  success  will  imme- 
diately come  certain  pleasurable  sensations  with  an  accom- 
panying large  draught  of  nervous  energy  towards  the 
organs  employed  in  eating,  &c.  That  is  to  say,  the  lines 
of  nervous  communication  through  which  the  diffused  dis- 
charge happened  in  this  case  to  pass,  have  opened  a  new 
way  to  certain  wide  channels  of  escape;  and,  consequently, 
they  have  suddenly  become  lines  through  which  a  large 
quantity  of  molecular  motion  is  drawn,  and  lines  which  are 
so  rendered  more  permeable  than  before.  On 

recurrence  of  the  circumstances,  these  muscular  movements 
that  were  followed  by  success  are  likely  to  be  repeated: 
what  was  at  first  an  accidental  combination  of  motions  will 
now  be  a  combination  having  considerable  probability. 
For  when  on  such  subsequent  occasion  the  visual  impres- 
sions have  produced  nascent  tendencies  to  the  acts  approxi- 
mately fitted  to  seize  the  object,  and  when  through  these 
there  are  nascently  excited  all  the  states,  sensory  and 
motor,  which  accompany  capture,  it  must  happen  that 
among  the  links  in  the  connected  excitations  there  will 
be  excitations  of  those  fibres  and  cells  through  which,  on 
the  previous  occasion,  the  diffused  discharge  brought  about 
the  actions  that  caused  success.  The  tendency  for  the 
diffused  discharge  to  follow  these  lines  will  obviously  be 
greater  than  before;  and  the  probability  of  a  successfully 
modified  action  will  therefore  be  greater  than  before. 
Every  repetition  of  it  will  make  still  more  permeable  the 
new  channels,  and  increase  the  probability  of  subsequent 
repetitions;  until  at  length  the  nervous  connexions  become 
organized. 

One  other  general  fact  must  be  insisted  upon.  As  was 
pointed  out  at  the  close  of  the  last  chapter,  advancing 
complexity   of  nervous   organization   necessitates   an   in- 


546  PHYSICAL  SYNTHESIS. 

creasing  quantity  of  excitations  that  do  not  cause  mo- 
tions. A  creature  in  which  the  compound  impression  pro- 
duced by  a  special  object  occupying  a  special  position, 
arouses  the  muscular  actions  effecting  capture  of  the 
object,  is  a  creature  which,  by  implication,  perpetually  re- 
ceives other  compound  impressions  from  objects  occupying 
other  positions.  Each  passing  thing,  as  well  as  every  thing 
passed,  sends  into  its  nervous  centres  variously-combined 
waves  of  disturbance,  which  course  through  their  fibres  and 
cells  in  ever-varying  combinations,  and  which,  having  no 
special  connexions  with  special  motor  adjustments,  simply 
diffuse  themselves  without  any  more  specific  effect  than 
that  of  augmenting  the  general  discharge  to  the  vital 
organs  and  muscular  system  at  large.  These  are  what, 
under  their  subjective  aspects,  we  call  feelings  and  ideas. 
And,  manifestly,  the  more  extensive  and  more  intricate  the 
central  plexus  grows,  the  more  detached  may  these  become 
from  the  actions — the  more  may  the  impressions  produced 
by  things  and  relations  reverberate  through  the  nervous 
system — the  more  may  there  arise  trains  of  thought. 

§  238.  Thus  much  premised,  let  us  try  to  conceive  how 
compound  co-ordination  passes  into  doubly-compound  co- 
ordination. A  broad  contrast  exists  between  the  two;  and 
we  shall  find  reasons  additional  to  those  before  given  (§  22) 
for  assigning  the  function  of  doubly-compound  co-ordination 
to  the  highest  nervous  centres. 

Let  Fig.  14  represent,  diagrammatically,  the  chief  ner- 
^,  Fig.  14.  vous  centre,  now  con- 

siderably evolved,  to 
which  afferent  fibres 
bring  all  orders  of 
epi-peripheral  feelings; 
and  from  which  effer- 
ent fibres  carry  to  the 
muscles,  the  stimuli  producing  their  appropriately-combined 


GENESIS  OF  DOUBLY-COMPOUND  NERVOUS  SYSTEMS.  547 

contractions.  And  suppose  that  while  other  parts  of  it  have 
for  their  functions  the  co-ordination  of  those  epi-peripheral 
feelings  which  are  least  relational,  the  part  A  coordinates 
the  most  relational  feelings  with  one  another  and  with  the 
appropriate  motions.  Or,  to  speak  specifically,  suppose 
that  A  is  the  part  of  the  central  plexus  where  the 
compound  visual  impressions  joined  with  the  compound 
impressions  from  the  eye-muscles,  are  brought  into  ad- 
justed relations  with  those  combined  muscular  feelings 
and  accompanying  feelings  of  touch  which  are  implied  by 
actions  of  the  limbs  under  guidance  of  the  eyes.  Then 
this  part  will  be  the  one  to  which  are  brought  the  most 
involved  clusters  of  feelings  in  ever-varying  proportions 
through  multitudinous  fibres;  and  one  from  which  issue 
through  multitudinous  fibres  in  ever-varying  proportions 
the  most  complicated  motor  impulses.  By  implication, 
each  special  adjustment  of  the  muscular  motions  to  the 
visual  impressions  must  have  in  this  part  its  co-ordinating 
plexus  of  converging  and  diverging  fibres  with  their  points 
of  junction — a  plexus  which,  while  having  many  elements 
in  common  with  the  plexuses  that  effect  other  co-ordina- 
tions, must  have  some  elements  peculiar  to  itself.  Whence 
it  follows  that  in  proportion  as  these  special  adjustments 
become  more  numerous,  there  must  be  a  multiplication  of 
the  elements  peculiar  to  each.  Consequently,  if  some  one 
group  of  these  co-ordinating  plexuses  takes  on  a  relatively 
great  development,  in  answer  to  the  relatively  immense 
sphere  for  new  adjustments  which  certain  environing  con- 
ditions furnish,  we  may  expect  one  part  of  this  region  A, 
to  become  protuberant,  as  at  A'.  And  if  these  multitudi- 
nous new  co-ordinating  plexuses,  growing  continually  more 
involved  as  they  grow  more  numerous,  admit  of  accumula- 
tion without  limit,  we  may  expect  a  growth  of  this  pro- 
tuberance. We  shall  soon  see  that  these  suppositions  and 
Inferences  are  paralleled  by  facts. 


548  PHYSICAL  SYNTHESIS. 

.  §  239.  Visual  impressions  and  their  concomitants  are  co- 
ordinated with  muscular  actions  and  their  concomitants  in 
two  ways — the  one  direct,  the  other  indirect.  The  direct 
co-ordinations  include  such  as  are  possible  to  a  creature  by 
changing  the  relative  positions  of  its  parts  without  changing 
its  position  in  space.  The  indirect  co-ordinations  include 
such  as  are  possible  only  by  changing  its  position  in  space 
as  well  as  changing  the  relative  positions  of  its  parts.  Let 
us  contrast  these  two  orders. 

Without  moving  from  the  spot  on  which  I  stand,  I  can 
explore  very  completely  all  things  within  reach  of  my  hands; 
and  the  combined  sets  of  feelings  I  get  have  a  certain  dis- 
tinctive character  of  great  significance.  From  each  of  these 
things  I  can  derive,  simultaneously,  four  clusters  of  sensa- 
tions— those  it  yields  my  retinae,  those  which  come  from  the 
specially-adjusted  muscles  of  my  eyes  and  head,  those  which 
come  from  the  muscles  of  the  arm  and  hand  by  which  I  lay 
hold  of  it,  and  those  given  me  by  its  contact  with  the  skin 
of  my  fingers.  The  order  of  co-ordinations  which  have 
this  important  character  in  common,  falls  into  two 
genera.  One  extensive  genus  of  quadruply-clus- 

tered  sensations  I  get  by  exploring  the  surfaces  of  my  body 
and  limbs.  I  can  adjust  my  eyes  so  as  to  see  my  hands 
while  they  move  over  my  feet;  I  can  use  one  hand  to 
examine  tactually  the  other  hand  and  arm,  and  can  observe 
with  my  eyes,  as  well  as  feel  with  my  muscles,  the  move- 
ments I  am  making.  The  distinctive  trait  of  quadruply- 
clustered  sensations  of  this  genus,  is  that  each  of  them 
contains  two  sets  of  tactual  sensations — one  set  coming 
from  the  parts  touched  and  the  other  from  the  parts  touch- 
ing them.  Indeed  we  may  say  that  they  are  thus  character- 
ized by  being  quintuply-clustered.  A  much  more 
extensive  genus,  distinguished  by  severally  containing  only 
a  single  tactual  cluster,  I  get  from  all  the  objects  that  exist 
within  a  range  of  three  feet  or  so  on  each  side  and  in  front, 
as  well  as  above  and  below.    I  can  stoop  down  to  touch  a 


GENESIS  OF  DOUBLY-COMPOUND  NERVOUS  SYSTEMS.  549 

thing  lying  near  my  feet  and  see  that  I  touch  it.  Without 
changing  my  place,  I  can  successively  raise  my  hand  to 
take  down  my  hat,  grasp  an  umbrella-handle,  touch  the 
back  of  a  hall  chair,  lay  hold  of  a  letter  waiting  for  me. 
Each  of  these  acts  gives  me  a  special  group  of  impressions 
of  colour  and  form,  a  special  group  of  muscular  feelings 
from  the  muscles  of  the  eyes  and  head,  a  special  group  from 
the  muscles  of  the  arm  and  hand,  a  special  group  from  the 
skin  of  the  fingers;  and  performance  of  each  act  implies 
special  co-ordination  of  the  special  groups.  Thus 

the  region  of  space  occupied  by  my  body  and  by  things 
immediately  around  it,  furnishes  numerous  compound  clus- 
ters of  sensations,  severally  having  the  peculiarity  that  their 
components  can  co-exist  in  consciousness.  Within  this  range 
the  conditions  are  such  that  an  object  which  yields  me  groups 
of  feelings  through  the  eye  and  through  the  eye-muscles, 
may,  if  I  go  through  a  certain  series  of  muscular  feelings, 
be  made  to  yield  me  a  group  of  tactual  feelings  joined  with 
a  group  of  feelings  of  muscular  tension;  and  these  addi- 
tional groups  may  be  brought  into  juxtaposition  in  con- 
sciousness with  the  first  groups,  without  these  first  groups 
heing  in  any  degree  changed. 

This  immense  order  of  co-ordinations  is  not  absolutely 
demarcated  from  the  far  more  immense  order  to  which  we 
shall  immediately  pass:  there  is  a  border  region  common  to 
the  two.  While  I  keep  my  feet  and  body  quite  fixed,  there 
is  a  definite  limit  to  the  range  of  my  hands  and  therefore  to 
the  regions  within  which  objects  can  yield  me  clustered  feel- 
ings co-ordinated  in  the  way  described.  But  by  leaning  for- 
ward or  on  one  side,  and  still  more  by  putting  out  one  foot 
while  keeping  the  other  stationary,  I  can  reach  additional  ob- 
jects, and  make  them  yield  me  combined  sets  of  feelings  very 
much  like  the  preceding  ones.  They  are  not  quite  like 
however;  for  each  of  them  contains  certain  additional 
elements — the  feelings  accompanying  the  partial  change  of 
place.    These  feelings  form  an  intercalated  set  of  links  by 


550  PHYSICAL  SYNTHESIS. 

which  the  visual  cluster  and  its  concomitants  are  brought 
into  a  relation  of  co-existence  with  the  tactual  cluster  and 
its  concomitants.  They  become  important  elements  in  the 
cluster  in  proportion  as  the  objects  are  difficult  to  reach 
without  moving  from  the  spot.  But  while  they  thus 
make  somewhat  indefinite  the  division  between  the  rela- 
tively-simple and  direct  co-ordinations  that  have  been 
described,  and  the  relatively-complex  and  indirect  co- 
ordinations to  be  next  dealt  with,  they  do  not  obliterate 
the  broad  contrast. 

For  now  mark  that  beyond  the  objects  I  see  within  easy 
reach,  and  beyond  the  objects  I  see  and  can  reach  by  leaning, 
or  by  putting  out  one  foot,  there  are  immensely-more 
numerous  objects  which  I  see  but  cannot  reach  without 
locomotion,  brief  or  prolonged.  While  I  stand  where  I  do, 
the  picture  on  the  opposite  wall  cannot  by  any  actions  of 
mine  be  made  to  yield  me  tactual  impressions:  I  put  out  my 
hands  towards  it,  I  bend  my  body  in  the  same  direction,  I  put 
one  foot  forward,  all  to  no  purpose.  That  I  may  touch  it,  I 
must  take  several  steps,  with  their  successive  groups  of  mus- 
cular feelings  in  my  legs  and  tactual  feelings  on  the  soles 
of  my  feet.  Thus  beyond  the  small  space  surrounding  my 
body,  there  lie  successive  concentric  portions  of  space  con- 
taining objects  which  after  being  seen  cannot  be  tactually 
explored  until  there  have  been  executed  certain  movements 
either  of  walking  or  running  or  leaping,  of  climbing  up  or 
getting  down — the  concomitant  feelings  varying  with  the 
direction  and  with  the  distance.  Manifestly,  we  have  here 
an  order  of  co-ordinations  vastly  larger  in  number  than  the 
first;  and  manifestly,  within  this  order  itself  the  co-or- 
dinations become  increasingly  numerous  and  increasingly 
complex  as  the  remoteness  increases.  More  than 

this  is  true.  Co-ordinations  of  this  higher  order  differ 
from  those  of  the  lower  order,  not  only  by  containing 
"lusters  of  locomotive  feelings  which  join  the  visual  cluster 
with  the  tactual  cluster:   they  differ  in  another  all-essential 


GENESIS  OP  DOUBLY-COMPOUND  NERVOUS  SYSTEMS.  551 

character.  For  tlie  original  visual  cluster  never  is 
brought  into  direct  relation  with  the  tactual  cluster. 
That  which  is  brought  into  direct  relation  with  the 
tactual  cluster  is  another  visual  cluster  (always  larger 
and  always  somewhat  different  in  form)  which  has  been 
substituted  for  the  original  cluster.  To  exemplify  by 
symbols — if  the  set  of  feelings  yielded  to  the  eye  and  eye- 
muscles  by  a  distant  object  be  called  a,  then  before  the  sets 
of  feelings  which  the  object  will  give  to  the  fingers  and 
arm-muscles  can  be  had,  a  must  go  through  a  series  of 
transformations  a,  A,  A,  A,  The  original  visual  cluster 
comes  to  be  co-ordinated  with  the  corresponding  tactual 
cluster,  only  through  a  series  of  visual  clusters  which  have 
a  certain  dependence  on  the  series  of  locomotive  clus- 
ters. Nor  is  this  all.  Like  changes  have  occurred 
in  the  visual  clusters  produced  by  other  objects  within  sight. 
These,  too,  have  undergone  enlargements,  and  alterations 
in  the  relations  of  their  parts;  and  many  of  them  have 
disappeared  laterally  from  the  field  of  view.  So  that 
establishment  of  one  of  these  adjustments  in  which  our 
eyes  guide  our  limbs  to  manipulate  things  at  a  distance, 
implies  co-ordinations  not  only  of  great  complexity  in 
comparison  with  those  required  for  manipulating  things 
close  to  us,  but  co-ordinations  that  are  made  more  com- 
plex by  the  introduction  of  new  elements  combined  in 
new  ways. 

§  240.  In  asking  how  such  higher  co-ordinations  are 
evolved  out  of  lower  ones,  and  how  the  structure  of  the 
nervous  system  becomes  progressively  complicated  in  such 
way  as  to  achieve  them,  the  cardinal  fact  to  be  remembered 
is  that  such  higher  co-ordinations  are  effected  by  mter- 
calations  of  new  clustered  states  between  the  original  clus- 
tered states.  Hence  it  is  to  be  expected  that  in  the  nervous 
apparatus  which  achieves  them,  there  must  be  intercalated 
plexuses  of  fibres  and  cells. 


552 


PHYSICAL  SYNTHESIS. 


If  in  Fig.  15,  we  suppose  a  to  be  the  place  to  whicli  are 
brought  through  many  fibres  the  clustered  sensations  yielded 


*v\ '( 


by  an  object  seen  within  reach ;  if  at  &  are  the  roots  of  fibres 
which  co-operate  when  this  object  is  grasped;  and  if  be- 
tween a  and  h  lie  the  co-ordinating  plexuses  through  which 
the  compound  sensory  excitements  lead  to  those  compound 
motor  excitements  that  cause  prehension  of  the  object,  not 
when  in  one  position  only  but  when  in  the  various  positions 
it  may  occupy  within  reach ;  what  will  happen  if  some  steps 
have  to  be  taken  before  the  visual  impression  is  followed  by 
prehension  ?  The  recipio-motor  and  dirigo-motor  changes 
gone  through  during  these  acts  of  locomotion,  imply  sundry 
compound  co-ordinations  with  their  correlative  plexuses. 
Whatever  sets  of  plexuses  are  successively  so  excited  that 
the  fibres  at  &  are  eventually  acted  on  in  the  way  re- 
quired to  cause  prehension,  it  must  happen  that  these 
sets  of  plexuses  will  become  a  network  of  lines  of  least 
resistance.  For  as  shown  in  §  237,  muscular  co-ordina- 
tions that  fail  have,  other  things  equal,  less  tendency  to  be 


GENESIS  OF  DOUBLY-COMPOUND  NERVOUS  SYSTEMS.  553 

repeated  when  the  same  conditions  recur  than  those  that 
succeed;  because  those  that  succeed  open  lines  of  discharge 
that  draw  off  large  amounts  of  molecular  motion.  Between 
o  and  &,  therefore,  there  will  arise  intercalated  sets  of 
plexuses  which  co-ordinate  the  successive  locomotions  and 
accompanying  visual  impressions  gone  through  between  the 
receipt  of  the  original  visual  impression  and  the  perform- 
ance of  the  eventual  prehension.  These  sets  of  plexuses 
must  be  very  numerous.  Supposing  the  object  to  be  one 
step  out  of  reach,  it  may  occupy  multitudinous  positions, 
high  or  low,  to  the  right  or  left;  and  the  required  co-ordi- 
nating plexus  for  each  position,  while  it  has  much  in  com- 
mon with  those  for  adjacent  positions,  must  have  something 
different.  But  the  space  between  a  and  &  is  already  occu- 
pied by  the  plexuses  which  effect  the  direct  co-ordinations. 
Hence  the  intercalated  plexuses  which  effect  these  indirect 
co-ordinations,  must  be  super-posed,  as  at  d;  and  the  co- 
ordinating discharges  must  take  roundabout  courses,  as 
shown  by  the  arrow. 

Each  such  position  being  reached  through  visual  and 
muscular  co-ordinations  which  are,  within  narrow  limits, 
the  same  for  all  members  of  a  species,  it  follows  that  there 
will  eventually  arise  in  the  species  an  organized  set  of  con- 
nexions such  that  the  visual  impression  produced  by  an 
object  in  that  position  and  the  muscular  actions  by  which  it 
may  be  grasped  are  definitely  correlated.  Little  by  little 
the  positions  composing  wider  and  wider  spheres  of  space 
may  come  to  be  thus  mentally  possessed;  while  there  is  a 
concurrent  enlargement  of  the  superior  co-ordinating  centre, 
by  the  intercalation  of  new  co-ordinating  plexuses  at  its 
periphery,  as  shown  at  e,  f,  g. 

§  241,  One  further  elaboration  remains.  To  render  the 
exposition  of  this  doubly-compound  co-ordination  less 
difficult  to  follow,  I  have  thus  far  treated  of  it  as  though 
the  relational  elements  involved  were  all  of  one  class.    But 


554  PHYSICAL  SYNTHESIS. 

in  reality  there  are  two  distinct  classes  of  them,  requiring 
distinct  centres  of  co-ordination. 

So  long  as  the  visual,  muscular,  and  tactual  impressions 
to  be  co-ordinated,  refer  exclusively  to  objects  within  reach, 
the  relations  of  succession  and  the  relations  of  co-existence 
are  not  definitely  parted.  It  is  true  that  when  anything 
within  this  range  has  yielded  its  visual  impressions,  a  certain 
series  of  muscular  states  has  to  be  gone  through  before  it 
yields  its  tactual  impressions.  But  when  these  have  been 
gone  through,  the  visual  impressions  as  at  first  received  and 
the  tactual  impressions  as  subsequently  gained,  co-exist — I 
can  continuously  gaze  at  the  thing  and  continuously  grasp 
it.  Moreover,  it  is  to  be  noted  that  in  all  these  cases  the 
order  of  sequence  in  the  consciousness  of  visual  impressions 
and  tactual  impressions  may  be  inverted — I  can  feel  the 
thing  first  and  see  it  after.  But  when  we  pass  from  these 
compound  co-ordinations  to  the  doubly-compound  co- 
ordinations, the  elements  of  succession  become  of  no 
less  importance  than  the  elements  of  co-existence. 
The  serial  states  gone  through  can  no  longer  be  dropped 
out  of  the  group,  and  the  sequence  from  visual  to  tactual 
cannot  by  any  possibility  be  inverted.  That  is  to  say, 
the  time-relations  and  the  space-relations  have  become 
distinctly  differentiated.  This  needs  some  further  explana- 
tion. When  I  walk  towards  an  object,  successive 
clusters  of  muscular  and  tactual  feelings  are  implied  by  the 
steps  I  make;  there  is  an  accompanying  series  of  gradually- 
enlarging  and  otherwise-changing  visual  impressions  from 
the  object  as  I  approach  it;  and  serial  changes,  more 
numerous  and  complicated,  are  produced  through  my  eyes 
by  adjacent  objects.  All  of  these  successions,  if  I  keep  my 
eyes  open,  and  certain  of  them  even  if  I  close  my  eyes, 
must  be  gone  through  before  the  tactual  impressions  to  be 
deceived  from  the  object  can  be  had.  The  visual  impression 
which  the  object  made  on  me  before  I  moved  towards  it, 
can  be  brought  into  relation  with  this  tactual  impression 


GENESIS  OP  DOUBLY-COMPOUND  NERVOUS  SYSTEMS.  555 

only  through  certain  serial  states;  and  these  not  only  form 
an  indispensable  chain  by  which  the  initial  and  terminal 
clusters  of  states  are  bound  together,  but  they  form  a  chain 
no  one  link  of  which  can  be  taken  out  of  its  place — their 
order  is  fixed.  Here  then  we  have  co-ordinations 

in  Space  and  co-ordinations  in  Time  uniting  to  achieve  the 
entire  co-ordination.  Before  a  step  is  taken  towards  the 
object,  the  impressions  made  by  it  and  all  things  around, 
stand  in  a  plexus  of  relations  of  co-existence.  Each  step 
implies  muscular  and  tactual  sequences  accompanied  by 
numerous  visual  sequences;  and  the  step  ends  by  bringing 
about  a  modified  plexus  of  co-existences.  The  two  orders 
of  relations  are  therefore  correlatives,  and  serve  to  interpret 
one  another.  Without  some  means  of  registering  the  series 
of  motions  to  be  gone  through  in  reaching  the  object,  there 
could  be  no  consciousness  of  its  distance.  Without  con- 
sciousness of  its  distance  the  muscular  feelings  gone  through 
could  have  no  meanings  in  thought  as  the  equivalents  of 
certain  spaces  traversed. 

But  the  differentiation  of  these  two  great  orders  of  rela- 
tions implies  a  differentiation  of  co-ordinating  centres. 
What  form  this  differentiation  takes  among  inferior  types  of 
animals  we  need  not  here  inquire.  In  the  highest  or  verte- 
brate type,  however,  there  are,  as  before  pointed  out,  reasons 
for  concluding  that  the  cerebellum  is  the  organ  of  doubly- 
compound  co-ordination  in  Space  while  the  cerebrum  is 
the  organ  of  doubly-compound  co-ordination  in  Time. 
To  the  reasons  before  assigned  for  this  conclusion  I  may 
here  add  some  others.  One  is  that  these  two 

supreme  nervous  centres  are  pedunculated  masses  growing 
out  of  the  enlarged  and  differentiated  extremity  of  the 
spinal  cord,  much  as  we  might  expect  the  centres  of 
doubly-compound  co-ordination  to  grow  out  of  the  centre 
of  compound  co-ordination.  Another  is  that  they 

preserve  a  general  relationship  in  their  development.  From 
fishes  upwards  their  evolution  goes  on,  if  not  with  equal  steps, 


556  PHYSICAL  SYNTHESIS. 

still  in  something  like  proportion.  This  is  a  trait  to  be  ex- 
pected; since  the  greater  developments  of  senses  and  limbs 
which  they  accompany  imply  simultaneously-increased  ex- 
periences of  time-relations  and  space-relations.  As  we 
approach  the  highest  vertebrate  types  the  cerebrum  develops 
at  a  greater  rate  than  the  cerebellum — a  fact  also  to  be 
anticipated.  For  in  the  simpler  vertebrate  animals  the  only 
time-relations  appreciable  are  those  disclosed  along  with 
space-relations  by  acts  of  locomotion.  But  in  the  more  com- 
plex vertebrate  animals,  whose  organized  experiences  of 
time-relations  thus  acquired  yield  measures  of  duration  of 
some  length,  other  orders  of  sequences  become  cognizable; 
and  the  nervous  centre  in  which  time-relations  are  co-ordi- 
nated thus  acquires  functions  peculiar  to  itself.  The 
compositions  of  these  two  great  centres  harmonize  with  the 
hypothesis.  The  process  described  in  §  240  implies  that  a 
centre  of  doubly-compound  co-ordination  will  be  evolved  by 
the  intercalation  of  plexuses  and  the  superposing  of  plexuses 
in  successive  strata — each  new  stratum  added  at  the  peri- 
phery of  the  mass  serving  to  re-coordinate  the  co-ordinating 
plexuses  below  it.  The  layers  of  cells  and  fibres  which 
the  cerebelhim  and  cerebrum  contain,  seem  fit  to  constitute 
appliances  of  this  kind.  Yet  again,  the  minute 
structure  of  the  cerebellum  is  more  regular  than  that 
of  the  cerebrum;  and  this  answers  to  the  comparative 
homogeneity  of  its  function.  Even  from  the  beginning 
some  such  difference  must  tend  to  arise.  The  ex- 
periences disclosing  relations  of  co-existence  in  space 
have  a  great  sameness;  and  though  those  which  bring  a 
consciousness  of  increasingly-remote  space  are  increasingly 
complex,  yet  the  complexity  increases  after  a  simple  sys- 
tematic manner.  If  all  movements  were  always  made  at  the 
same  velocities,  then  the  time-relations  disclosed  in  loco- 
motion would  be  as  uniform  as  the  space-relations;  and  the 
nervous  centre  which  co-ordinated  the  actions  to  them  might 
be  equally  homogeneous  in  structure.    But  since  the  move- 


GENESIS  OF  DOUBLY-COMPOUND  NERVOUS  SYSTEMS.  557 

ments  are  very  variable  in  speed,  not  only  as  made  on 
different  occasions,  and  as  made  by  different  muscles,  but 
even  as  made  by  the  same  muscle  during  different  parts 
of  its  contraction,  there  is  a  cause  of  heterogeneity  in  the 
co-ordination  of  time-relations  which  we  may  expect  to 
be  expressed  by  some  heterogeneity  in  the  nervous  plexuses 
effecting  them.  Still  more  must  such  heterogeneity  be 
looked  for  when  we  pass  to  time-relations  of  a  higher 
order.  The  sequences  that  become  appreciable  when  intelli- 
gence becomes  high,  are  sequences  of  very  numerous  orders, 
of  very  various  lengths,  and  between  terms  of  very  various 
complexities;  as  instance  the  contrast  between  the  suc- 
cession of  sounds  in  speech  and  the  succession  of  the 
seasons.  After  contemplating  the  multitudes  of  these  time- 
relations  occurring  between  all  kinds  of  things,  differing 
enormously  in  their  durations,  and  having  countless  degrees 
of  heterogeneity,  we  shall  not  be  surprised  to  find  that  the 
organ  of  doubly-compound  co-ordination  in  time  presents 
marked  unlikenesses  of  a  minute  structure  in  its  different 
regions. 

§  242.  I  need  not  attempt  further  to  complicate  this  syn- 
thesis by  including  those  actions  in  which  tastes,  odours, 
sounds,  &c.,  play  a  part.  Already  in  seeking  to  build  up  a 
general  conception  of  the  process  of  nervous  evolution  in  its 
higher  stages  I  have  elaborated  the  argument  quite  far 
enough — perhaps  too  far. 

Let  me,  indeed,  disclaim  the  endeavour,  which  some  may 
suppose  I  have  been  making,  to  explain  the  process  in  full. 
My  purpose  has  been  rather  to  make  the  possibility  of  such 
a  process  conceivable;  and  I  have  taken  specific  cases  and 
used  concrete  language  because  so  only  could  I  make  myself 
understood.  The  actual  genesis  has  been  much  more  in- 
volved than  that  which  I  have  described — so  involved  that 
a  true  delineation,  even  could  it  be  made,  would  be  scarcely 
comprehensible. 


558  PHYSICAL  SYNTHESIS. 

It  may  be  well  here  to  repeat  the  caution  against  attach- 
ing literal  meanings  to  some  of  the  terms  used.  The  inter- 
pretations of  such  phrases  as  "  nervous  connexions  "  and 
"  plexuses  of  fibres,"  must  not  be  too  strict.  We  are  not 
warranted  by  observation  in  supposing  that  "  connexions  " 
and  "  plexuses  "  are  quite  definite;  nor  does  the  argument 
require  us  so  to  suppose  them.  That  which  the  argument 
requires  is  a  plexus  of  chmi/nels  through  which  compound 
stimuli  may  be  united  and  re-distributed  into  compound 
impulses;  and  these  channels  may  be  formed  partly  of 
distinct  fibres  and  partly  of  unmarked  lines  of  discharge 
through  the  imbedding  protoplasm.  Indeed  it  is  manifest 
that  in  the  nervous  structures  which  carry  on  the  higher 
mental  actions  the  connexions  must  have  all  degrees  of 
definiteness,  and  that  the  greater  part  of  them  must  be 
very  indefinite — the  ultimate  ramifications  of  the  channels 
through  which  the  discharges  find  their  ways  must  be  in- 
visible. 


CHAPTEK  YI. 

FUNCTIONS  AS  BELATED  TO  THESE  STRUCTUEES. 

§  243.  In  tracing  out  the  genesis  of  nervous  structures, 
a  good  deal  has  been  implied  respecting  the  genesis  of  ac- 
companying functions.  Fully  to  understand  the  natures  of 
these  functions,  however,  it  is  needful  to  contemplate  them, 
by  themselves  in  their  ascending  succession. 

Throughout  the  foregoing  argument,  functions,  when  re- 
ferred to,  have  been  expressed  in  physiological  language. 
It  remains  to  translate  this  into  psychological  language. 
What  have  been  considered  as  increasingly-complex  nervous 
actions  we  have  now  to  consider  as  increasingly-complex 
mental  states. 

§  244.  In  reflex  action  of  the  earliest  kind,  a  single 
stimulus  at  the  periphery  of  an  afferent  nerve  sends  a  wave 
of  molecular  change  to  a  nerve-centre,  whence,  through 
ready-made  channels,  the  wave  instantly  escapes  in  a  more 
or  less  augmented  form  along  an  efferent  nerve  and  excites 
some  organ  or  organs — contractile  organs  being  those  to 
which  we  may  here  confine  our  attention.  And  such  fully- 
established  reflex  action,  not  delayed  a  moment  in  its  course, 
is  unconscious. 

A  compound  reflex  action  that  is  fully  established, 
though  implying  the  reception  of  peripheral  stimuli  by 
several  afferent  nerves,  the  passage  of  resulting  waves 
87  559 


560  PHYSICAL  SYNTHESIS. 

through  a  ganglionic  net-work,  and  the  emission  of  dis- 
charges through  motor  nerves  more  or  less  numerous,  is  also 
unconscious — the  passage  through  the  central  plexus  not 
occupying  the  time  which  consciousness  implies. 

But  compound  reflex  actions  in  which  the  co-operating 
stimuli  produce  the  combined  motor  impulses  only  after 
a  pause,  caused  by  incompleteness  in  the  permeability  of 
the  central  plexus,  may  be  presumed  to  have  some  accom- 
panying consciousness — some  feeling  that  occupies  the 
interval  between  the  receipt  of  the  impressions  and  the 
escape  of  the  discharges. 

Each  compound  reflex  action,  accompanied  at  first  by 
consciousness,  but  made  by  perpetual  repetition  automatic 
and  unconscious,  becomes  a  step  towards  reflex  actions  still 
more  compound.  These,  during  their  stage  of  partial  estab- 
lishment, imply  consciousness  that  is  somewhat  more  com- 
plex and  varied  than  the  earlier  consciousness  which  has 
been  lost  in  automatic  action. 

Besides    the    consciousness    accompanying   those    reflex 
actions  which  are  but  partially  established,  there  is  im- 
plied a  much  larger  body  of  consciousness.    For  as  already 
shown,    the    sense-organs    that    occasionally    receive    the 
special   combinations   of  stimuli   which   cause   automatic- 
ally certain  adjusted  contractions  of  muscles,   are  sense- 
organs  that  perpetually  receive  stimuli  not  specially  coni- 
bined — stimuli  which  are  therefore  sending  into  the  central - 
plexuses,    waves    of    disturbance    that    are    not    instantly 
draughted  off  to  particular  motor  organs.     These,  dwell- 
ing in  the  nervous  centres  as  long  as  the  stimuli  continuej 
to  be  received,  imply,  as  their  psychical  correlatives,  what* 
we  call  sensations,  or  something  homologous  with  them. 

The  great  mass  of  the  sensations  thus  produced  by  ex- 
ternal objects  on  a  creature  that  has  reached  this  stage  | 
of  evolution,  constitute  an  unorganized  consciousness — a 
consciousness  of  which  very  few  components  have  any  spe- 
cific  order   or   definite   meaning.      Impressions    received  I 


FUNCTIONS  AS  RELATED  TO  THESE  STRUCTURES.    561 

through  the  eyes  of  such  a  creature  are  mostly  mere 
patches  of  colour,  associated  very  feebly,  if  at  all,  with  the 
tactual  impressions  yielded  by  the  same  objects.  Only  in 
the  cases  of  those  environing  things  to  which  the  com- 
pound reflex  actions  or  instincts  are  either  adjusted  or  in 
course  of  adjustment,  does  this  raw  material  of  mind  rise 
into  nascent  intelligence. 

This  nascent  intelligence  exists,  however,  not  only  where 
new  compound  reflex  actions  are  being  established,  but  also 
where  an  established  compound  reflex  action  is  incipiently 
excited.  Suppose  such  an  animal  as  we  have  been  consider- 
ing, sees  approaching  some  small  creature  of  the  kind  on 
which  it  preys.  Then,  while  this  small  creature  is  coming 
nearer,  but  before  it  has  reached  the  point  at  which  its 
visual  image  arouses  the  reflex  action  that  effects  its  seizure, 
a  series  of  visual  images,  increasing  in  size  and  definiteness, 
must  be  yielded  by  it;  and  it  must  yield  an  accompanying 
series  of  stimuli  to  the  eye-muscles.  Though  the  reflex 
action  takes  place  only  when  the  retinal  and  muscular  im- 
pressions become  combined  in  a  certain  way,  yet  during 
approach  to  the  required  combination  the  reflex  action  is 
tending  to  arise — there  is  a  gradually-increasing  excitement 
of  the  nervo-motor  apparatus  which  will  presently  perform 
the  reflex  action.  The  effect  does  not  stop  here.  Through 
the  established  connexions  there  is  propagated  a  gradually- 
increasing  excitement  of  the  nervo-motor  apparatus  which 
catching  the  prey  will  bring  into  play — there  are  produced 
faint  revivals  of  the  tactual  and  gustatory  states  which 
capture  of  such  prey  has  on  past  occasions  yielded.  Thus, 
then,  results  what  we  call  perception;  for  we  have  here  a 
cluster  of  real  feelings  caused  by  the  presented  object, 
joined  with  a  cluster  of  ideal  feelings,  representing  certain 
other  real  feelings  which  the  object  has  before  produced 
and  can  again  produce. 

Perceptions  of  this  order  are  gradually  extended  to  other 
surrounding  things.     The  apparatus  effecting  the  percep- 


562  PHYSICAL  SYNTHESIS. 

tions  which  are  followed  by  reflex  actions,  Is  capable  of 
effecting  perceptions  which  are  not  followed  by  reflex 
actions.  Clustered  visual  feelings  yielded  by  inanimate 
bodies,  are,  like  those  yielded  by  animate  bodies,  apt  to 
be  joined  in  experience  with  clustered  feelings  yielded  by 
them  to  the  skin  and  muscles;  and  the  two  clusters  so 
excited,  though  less  frequently  forming  a  sequence,  even- 
tually become  correlated  in  a  similar  way.  Thus  the  chaotic 
impressions  received  from  environing  objects,  are  slowly 
evolved  into  a  slightly-organized  consciousness  of  environ- 
ing objects. 

§  245.  Between  a  perception  physiologically  considered 
and  a  perception  psychologically  considered,  the  relation 
now  becomes  manifest.  We  see  that  a  perception  can  have 
in  a  nerve-centre  no  definite  localization,  but  only  a  diffused 
localization.  No  one  excited  fibre  or  cell  produces  conscious- 
ness of  an  external  object:  the  consciousness  of  such  ex- 
ternal object  implies  excitement  of  a  plexus  of  fibres  and 
cells.  And  not  only  does  this  plexus  of  fibres  and  cells  differ 
with  every  different  object,  but  it  differs  with  every  differ- 
ent position  of  the  same  object.  A  clear  understanding  of 
this  may  be  conveyed  by  an  illustration. 

A  good  piano  has,  including  semi-tones,  between  eighty 
and  ninety  notes — say,  for  convenience  of  calculation,  a 
hundred:  to  which  last  number,  indeed,  a  pedal  piano 
reaches  nearly,  if  not  quite.  Such  a  piano,  then,  if  its  keys 
are  struck  singly,  is  capable  of  yielding  but  a  hundred 
different  tones.  If  its  keys  be  struck  two  together,  the 
different  combinations  that  are  possible  amount  to  4,950; 
if  three  together,  to  161,700;  if  four  together,  to  3,921,225; 
if  five  together,  to  75,287,520.  These  numbers,  increasing 
thus  with  enormous  rapidity  as  the  complexity  of  the  chords 
increases  (until  we  reach  chords  of  fifty  notes,  after  which 
they  begin  to  diminish),  yield,  when  added  up,  a  total 
requiring  a  row  of  thirty  figures  to  express  it — a  million, 


FUNCTIONS  AS  RELATED  TO  THESE  STRUCTURES.    563 

million,  million,  million,  millions.  Each  combination  is, 
considered  as  a  set  of  sonorous  vibrations,  unlike  every 
other;  and  though  the  majority  of  them  are  but  in- 
conspicuously different,  yet  there  are  millions  of  mil-, 
lions  of  them  that  differ  in  well-marked  ways.  So 
that  out  of  this  comparatively-simple  structure  a  prac- 
tically-unlimited number  of  functional  effects  is  pro- 
ducible. If  now,  instead  of  the  keys  of  the  piano, 
we  suppose  a  cluster  of  such  sensitive  bodies  as  those 
which  form  the  retina;  if  instead  of  the  appliances  which 
convey  to  the  strings  the  impacts  given  to  the  keys,  we 
take  the  fibres  that  carry  to  the  optic  centres  the  impres- 
sions made  on  these  retinal  elements;  and  if  instead  of 
strings  made  to  vibrate  we  put  ganglion  corpuscles  excited 
by  the  impulses  they  receive;  we  shall  see  that  a  percep- 
tion may  be  compared  to  a  musical  chord.  As  by 
striking  a  certain  set  of  keys  there  is  brought  out  a  par- 
ticular combination  of  tones,  simple  or  complex,  con- 
cordant or  discordant;  so  when  a  special  object  seen 
strikes  by  its  image  a  special  cluster  of  retinal  elements, 
and  through  them  sends  waves  to  the  fibres  and  cells 
of  a  corresponding  central  plexus,  there  results  the  special 
aggregate  of  feelings  constituting  perception  of  the  object. 
Without  further  detail  the  reader  will  see  how  it  thus  be- 
comes possible  for  a  limited  number  of  fibres  and  cells  to 
become  the  seat  of  a  relatively-unlimited  number  of  per- 
ceptions. 

While  it  thus  in  a  general  way  illustrates  perception  under 
one  of  its  aspects,  the  action  of  a  piano  fails  wholly  to  illus- 
trate it  under  another  of  its  aspects;  as  the  motions  of  a 
dead  mechanism  must  necessarily  fail  to  represent  in  full 
the  functions  of  a  living  one.  For,  as  above  pointed  out,  a 
perception  is  formed  only  when  a  cluster  of  real  feelings 
excites  a  correlated  cluster  of  ideal  feelings.  If  our  piano 
were  so  constituted  that  after  any  two  chords  had  been 
repeatedly  sounded  in  succession,  there  resulted  some  stme- 


564  PHYSICAL  SYNTHESIS. 

tural  change,  such  that  when  the  first  of  these  chords  was 
again  evoked  by  a  performer's  hands  a  faint  echo  of  the 
second  chord  followed  without  aid  from  the  performer's 
hands,  the  parallel  would  be  nearer.  We  should  then  have 
something  analogous  to  what  happens  when  a  nervous 
plexus  excited  by  certain  properties  of  an  object,  diffuses  its 
excitement  to  another  plexus  that  has,  on  previous  occa- 
sions, been  excited  by  other  properties  of  the  object.  And 
here,  indeed,  while  we  are  giving  the  rein  to  imagination,  let 
us  take  a  wider  licence — let  us  suppose  that  several  chords 
struck  in  succession,  thus  aroused  faint  repetitions  of  the 
many  following  chords  forming  the  rest  of  the  music  to 
which  they  belonged.  We  shall  then  be  helped  to  conceive 
more  nearly  how  the  elements  of  perceptions  become  linked 
together.  And  on  contemplating  the  infinity  of  musical 
effects  obtained  by  combining  different  compound  chords 
in  ever-varying  successions,  we  shall  get  some  idea  of  the 
infinity  of  perceptions  that  arise  by  the  organizing  of 
clusters  of  co-existing  feelings  in  endlessly  changing 
sequences. 

§  246.  We  may  now  pass  from  perceptions  to  ideas^ 
properly  so-called.  Though  every  true  perception  along 
with  its  presentative  feelings  necessarily  contains  certain 
representative  feelings,  these  do  not  at  first  become  what  we 
usually  understand  by  ideas.  They  have  not  the  detach- 
ableness  which  distinguishes  ideas  that  are  fully  developed. 
They  can  be  called  into  existence  only  by  the  sense- 
impressions  with  which  they  are  directly  connected  in 
experience;  and  they  can  continue  to  exist  only  so  long  as 
these  continue  to  exist.  To  return  to  our  illustration — a 
creature  so  constructed  as  to  be  capable  of  nothing  beyond 
the  compound  co-ordinations  just  described,  resembles  a 
piano  that  is  silent  until  touched  by  the  hands  of  the  per- 
former. Its  nervous  system  is  played  upon  by  external 
objects,  the  clustered  properties  of  which  draw  out  answer- 


FUNCTIONS  AS  RELATED  TO  THESE  STRUCTURES.    565 

ing  chords  of  feelings,  followed  by  faintly-reverberating 
chords  of  further  feelings;  but  it  is  otherwise  passive — it 
cannot  evolve  a  consciousness  that  is  independent  of  the 
immediate  environment. 

How  does  such  independent  consciousness  become  pos- 
sible? When  do  ideas,  rightly  so-called,  arise?  They  arise 
when  compound  co-ordination  passes  into  doubly-compound 
co-ordination.  They  grow  distinct  in  proportion  as  the 
correspondence  extends  in  Space  and  Time.  They  acquire 
a  separateness  from  direct  impressions  as  fast  as  there 
increase  those  series  of  clustered  sensations  which  unite 
the  visual  sensations  received  from  objects  out  of  reach 
with  the  tactual  sensations  afterwards  yielded  by  such  ob- 
jects. They  are  the  necessary  concomitants  of  that  process 
by  which,  through  intercalated  psychical  states,  there  is 
established  a  mediate  relation  between  psychical  states 
that  cannot  be  brought  into  immediate  relation.  And 
they  have  for  their  seats  those  intercalated  plexuses  which 
co-ordinate  the  co-ordinating  plexuses  previously  exist- 
ing. That  is  to  say,  ideas  form  a  larger  and  larger  por- 
tion of  consciousness  as  fast  as  there  develop  those  two 
great  pedunculated  nerve-centres  which  distinguish  the 
superior  animals;  ideas  become  more  multitudinous  and 
more  separable  from  direct  sense-impressions  as  these 
centres  increase  in  size  and  structure ;  and  eventually,  when 
these  centres  are  highly  evolved,  ideas  admit  of  combina- 
tion into  trains  of  thought  that  are  quite  independent  of 
present  external  perceptions. 

By  carrying  a  step  further  the  illustration  used  in  the  last 
section,  we  may  now  get  a  better  notion  of  the  parts  which 
the  cerebrum  and  cerebellum  play  in  mental  processes. 
For  just  as,  by  the  actions  of  appropriate  mechanisms 
joined  to  them,  musical  instruments  of  certain  kinds  are 
made  to  yield  musical  combinations  without  the  hands  of 
the  performer;  so,  through  the  workings  of  these  great 
appended  nerve-centres,  there  are  called  out  from  the 


566  PHYSICAL  SYNTHESIS. 

centres  below  them,  trains  of  consciousness  independent  of, 
or  additional  to,  those  aroused  by  impressions  on  the  senses. 
To  make  the  parallelism  understood,  let  me  describe, 
at  some  length,  one  order  of  these  mechanical  appli- 
ances. Every  one  has  watched  the  revolving 
barrel  of  a  musical  box,  as  its  pins  strike,  in  successive  com- 
binations, the  vibrating  metal  tongues;  and  every  one  sees 
that  the  set  of  pins,  arranged  in  a  special  way,  represents, 
in  a  sense,  the  harmonized  melody  produced.  By  moving 
the  barrel  a  small  distance  longitudinally,  another  set  of 
pins,  clustered  in  another  way,  is  brought  into  position, 
ready,  when  the  barrel  revolves,  to  bring  out  another  set  of 
chords  and  cadences;  and  so  on.  The  mechanical  arrange- 
ment in  this  case,  restricts  very  closely  the  number  of 
musical  combinations  which  the  barrel  can  contain,  or 
rather,  which  its  clustered  pins  can  represent.  But  it  is 
easy  to  conceive  an  arrangement  permitting  indefinite 
multiplication  of  such  combinations.  If  we  suppose  the 
sheet  of  metal  forming  the  surface  of  the  barrel  to  be  cut 
longitudinally,  and  unrolled  into  a  flat  surface  without  dis- 
turbing the  inserted  pins,  it  is  clear  that  if  this  flat  surface 
were  moved  down  vertically  in  front  of  the  metal  tongues, 
between  rollers  which  kept  it  properly  in  place,  its  pins  might 
be  made  to  strike  the  metal  tongues  just  as  they  now  do. 
And  it  will  at  once  be  seen  that  any  number  of  such  flat 
plates,  all  having  differently-clustered  pins  representing 
different  harmonized  melodies,  might  be  made  to  pass 
through  the  rollers.  A  further  complication,  needed 
to  complete  the  analogy,  will  now  be  readily  under- 
stood. In  the  musical  box,  the  chords  and  sequences  admit 
of  being  produced  only  by  these  pre-adjusted  appliances. 
But  there  exists  a  species  of  mechanical  piano  capable  of 
being  played  upon  in  the  ordinary  way,  and  also  of  having 
dra\vn  from  it  an  unlimited  number  of  pieces  of  music  after 
a  method  akin  to  that  last  described.  Looking  much  like 
an  ordinary  cottage-piano,  this  instrument  has,  protruding 


FUNCTIONS  AS  RELATED  TO  THESE  STRUCTURES.    567 

through  its  top,  a  second  set  of  small  keys  that  stand 
vertically  in  a  closely-packed  row.  When  certain  adjacent 
rollers  fitly  adjusted  are  turned  round,  a  flat  board 
placed  beneath  them  is  drawn  along  horizontally,  so 
that  the  specially-arranged  metal  pins  on  its  under  sur- 
face, by  striking  this  row  of  keys,  produce  the  successive 
chords  and  phrases  of  an  air.  And  such  boards,  each  in- 
capable of  emitting  a  note,  but  having  in  the  arrangements 
of  its  parts  a  latent  power  of  eliciting  from  the  piano  a  spe- 
cial piece  of  music,  may  be  multiplied  without  end.*  If, 
now,  we  compare  one  of  these  tune-boards  to  the  nervous 
plexus  of  fibres  and  cells  which  effects  a  doubly-compound 
co-ordination;  and  if  we  consider  the  cerebrum  and  cere- 
bellum as  like  vast  magazines  of  such  tune-boards,  duly 
classified  and  adjusted  for  being  brought  into  instant 
action;  our  comparison  will  fail  in  several  ways  to  convey 
an  adequate  conception.  Instead  of  appliances  each  having 
its  quite  distinct  and  quite  independent  combination,  we 
require  appliances  that  are  not  quite  distinct  or  indepen- 
dent, but  have  larger  or  smaller  parts  of  their  combinations 
in  common.  Further,  we  must  imagine  kindred  appliances 
of  a  higher  order,  which  do  not  themselves  elicit  the 
harmonized  melodies,  but  which  re-combine  in  various 
ways,  simultaneous  and  successive,  the  appliances  that  do 
this — represent,  as  it  were,  whole  concerts  of  them  specially 
arranged ;  and  so  on  in  still  higher  gradations.  We  require 
also  to  suppose  that  the  potential  musical  pieces,  and  com- 
binations of  such  pieces,  thus  constituted,  admit  of  being 
brought  into  action  not  only  apart  from,  but  also  along  with, 
the  original  keys;  so  that  when  some  bars  have  been  per- 
formed by  the  pianist,  this  attached  apparatus,  thereby 
set  going,  gives  out  in  faint  tones  few  or  many  of  the 
bars  previously  connected  with  those  sounded.     Above  all, 

*  A  piano-mScanique  of  this  kind  was  shown  in  the  French  Depart- 
ment of  the  Great  Exhibition  of  1851  by  A.  Debain.  1  find  that  Cramer 
is  now  his  English  agent  for  the  sale  of  them. 


568  PHYSICAL  SYNTHESIS. 

we  have  to  assume  a  process  unapproachable  by  any  appa^ 
ratus  of  human  manufacture — a  process  through  which 
repetition  of  the  actions  serves  to  establish  the  con- 
nexions. But  though  the  illustration  fall  short 
in  so  many  ways,  it  helps  us  to  imagine  the  kind  of  re- 
lation which  the  highest  nervous  structures  bear  to  lower 
ones.  We  are  enabled  by  it  to  understand  better  how 
thinking  goes  on  along  with,  or  apart  from,  the  perception 
of  external  things.  It  removes  the  difficulty  of  conceiving 
that  the  centre  of  compound  co-ordination,  to  which  all 
centripetal  nerves  bring  their  impressions  and  from  which 
issue  throagh  centrifugal  nerves  motor  impulses,  continues 
to  the  last  to  be  the  sentient  centre.  "We  see  that  while  this 
centre  is  the  seat  of  the  sensations  aroused  by  external 
stimuli,  and  the  place  in  which  these  are  brought  into  re- 
lation with  other  sensations  similarly  aroused;  it  is  also  the 
place  in  which  such  feelings  and  relations  are  feebly  re- 
aroused,  in  the  same  combinations  and  in  other  combinations, 
by  discharges  through  the  fibres  of  the  overlying  cerebral 
masses.  We  see,  in  short,  that  the  medulla  oblongata  (with 
its  subordinate  structures)  while  played  upon  through  the 
senses  by  external  objects,  is  simultaneously  played  upon 
by  the  cerebrum  and  cerebellum  :  so  producing  the  thought- 
consciousness  that  accompanies  sense-consciousness. 

§  24 Y.  One  further  question  to  be  asked  is — What,  from 
this  point  of  view,  is  an  emotion  ?  If,  recalling  the  conclu- 
sion reached  in  §§  213-216,  we  join  with  it  the  above  infer- 
ences, we  shall,  I  think,  get  a  satisfactory  answer. 

As  said,  and  tacitly  implied,  in  various  places,  the  co- 
ordinating plexus  by  which  any  cluster  of  sensations  is  made 
to  excite  the  appropriate  muscular  actions,  must  in  great 
measure  coincide  with  other  plexuses  by  which  allied  clus- 
ters of  sensations  are  made  to  excite  allied  actions.  In  pro- 
portion as  the  external  things  responded  to  have  much  in 
common,  and  the  required  motions  have  much  in  common. 


FUNCTIONS  AS  RELATED  TO  THESE  STRUCTURES.  569 

the  plexuses  that  effect  the  adjustments  will  have  much  in 
common.  Not  only  of  the  plexuses  which  effect  compound 
co-ordinations  must  this  be  true:  it  must  be  true  also  of 
those  which  effect  doubly-compound  co-ordinations.  But 
the  more  involved  the  co-ordinations  become  the  less  definite 
will  be  these  agreements;  since,  along  with  the  progressive 
compounding  of  impressions  and  motions,  there  necessarily 
goes  multiplication  of  differences  in  details.  Let  us  ex- 
emplify. 

The  plexuses  which  co-ordinate  the  visual  impressions 
yielded  by  an  apple  on  the  table,  with  the  motor  acts  re- 
quired to  grasp  it  and  with  the  ideas  of  tactual  and  gusta- 
tory sensations  it  will  yield,  are  nearly  the  same  as  certain 
plexuses  that  have  before  worked  together.  Those  which 
establish  the  consciousness  of  the  apple's  relative  position 
in  space,  answer  almost  exactly  to  those  which  have  estab- 
lished the  consciousness  of  that  relative  position  in  space 
when  occupied  by  other  objects,  alike  in  the  experience  of 
the  individual  and  in  the  experience  of  antecedent  indi- 
viduals; and  those  which  establish  the  consciousness  of  the 
apple's  smoothness,  hardness,  odour,  and  taste,  as  related 
to  its  form  and  colour,  are  the  same  within  narrow  limits 
as  those  which  have,  in  previous  experiences  of  the  indi- 
vidual, done  the  like.  Along  with  this  agreement  of  the 
plexuses  the  consciousness  is  definite.  Take  now, 

in  contrast,  the  nervous  structures  excited,  and  the  corre- 
lative mental  state  produced,  by  an  animal  that  threatens 
attack — say  a  fierce  dog.  It  growls,  it  puts  back  its  ears, 
it  shows  its  teeth,  it  advances  in  an  active  way.  But 
the  motions,  the  gestures,  and  the  sounds  it  makes,  while 
they  considerably  resemble  those  made  by  other  dogs  on 
other  occasions,  do  not  coincide  with  them  by  any  means 
closely.  Much  less  do  they  agree  with  those  made  by 
another  animal  in  a  similar  mood — say  an  angry  bull; 
though  in  the  rapidity  of  the  approach,  in  the  energy  of 
the  movements,  in  the  loudness  of  the  sounds,  there  is  a 


570  PHYSICAL  SYNTHESI& 

general  similarity.  And  they  differ  still  more  from  the 
demonstrations  made  by  a  furious  man;  though  these,  too, 
have  in  common  with  them  the  threatening  advance, 
the  violent  actions,  and  the  loud  harsh  tones.  It  follows, 
then,  that  the  co-ordinating  plexuses  brought  into  play  by 
perception  of  an  approaching  enemy  on  successive  occasions, 
never  coincide  in  detail,  even  when  the  enemy  is  of  the 
same  kind;  and  their  non-coincidence  is  great  in  pro- 
portion as  the  enemies  are  of  kinds  differing  in  their 
appearances  and  modes  of  action.  Let  us  next  consider 
what  happens  if  the  threatened  attack  becomes  an  actual 
attack.  There  is  pain,  there  is  struggling,  there  are 
cries,  perhaps  of  anger,  perhaps  of  agony — all  implying 
violent  excitements  of  particular  plexuses.  But  the  plexuses 
excited  do  not  coincide  with  those  before  excited  by  such 
attacks.  The  pains  do  not  come  from  the  same  injured 
parts;  the  struggles  are  unlike  in  their  combinations;  the 
sounds  emitted  differ  in  pitch,  or  intensity,  or  order — 
usually  in  all  of  these.  So  that  though  the  plexuses 
have  much  in  common  they  have  a  great  deal  not  in 
common.  Mark  further  that  these  agreements  and  dis- 
agreements obtain  not  in  the  experiences  of  each  individual 
only,  but  in  the  experiences  of  successive  individuals. 
Generation  after  generation  the  approach  of  enemies  has  ex- 
cited certain  nervous  structures  in  ways  much  alike  in  some 
few  general  characters,  but  unlike  in  multitudinous  special 
characters;  and  there  has  followed  the  excitement  of  other 
structures  that  have  similarly  agreed  in  part  and  disagreed 
in  part.  What  has  resulted?  Each  plexus  has  been 
inherited  in  the  form  of  a  well-organized  set  of  connexions 
in  the  midst  of  many  less  definite  connexions,  obscured  by 
multitudinous  feeble  connexions;  and  the  inherited  central 
connexions  of  the  plexus  first  excited,  are  definitely  con- 
nected with  the  inherited  central  connexions  of  the  similarly- 
constructed  plexus  that  is  habitually  excited  after  it.  The 
accompanying  subjective  results  are  these.    The  conscious- 


I 


FUNCTIONS  AS  RELATED  TO  THESE  STRUCTURES.    571 

ness  of  an  approaching  body  making  sounds  and  motions 
of  a  certain  kind,  is  followed  by  a  consciousness  of  painful 
states,  sensory  and  motor,  having  no  definite  localizations. 
The  immediate  perception,  with  the  crowd  of  ideas  resulting 
from  preceding  similar  perceptions,  arouses  not  only  ideas 
of  particular  pains  that  have  before  followed  such  percep- 
tions in  the  life  of  the  individual;  but  through  the  inherited 
organization  it  arouses  an  indefinable  sense  of  ill — a  cloud 
of  dim  feelings  of  suffering  that  cannot  be  reduced  to  form 
because  they  have  not  been  personally  experienced — the 
emotion  oifea/r.  And  with  the  primitive  form  of  fear,  thus 
physically  organized  and  psychically  constituted,  there  are 
afterwards  integrated  the  higher  and  more  involved  forms 
of  fear;  all  of  which  have  for  their  central  element,  ideal 
feelings  of  pain  or  discomfort  that  are  unlocalizable  and 
therefore  vague. 

Respecting  emotions  it  has  only  to  be  added  that  they, 
like  ideas,  result  from  the  co-ordinating  actions  of  the 
cerebrum  and  cerebellum  upon  the  medulla  oblongata  and 
structures  it  presides  over.  As  the  plexuses  in  these 
highest  nervous  centres,  by  exciting  in  distinct  ways  special 
sets  of  plexuses  in  the  inferior  centres,  call  up  special  sets 
of  ideal  feelings  and  relations;  so,  by  simultaneously  ex- 
citing in  diffused  ways  the  general  sets  of  plexuses  to  which 
these  special  sets  belong,  they  call  up  in  vague  forms  the 
accompanying  general  sets  of  ideal  feelings  and  relations — 
the  emotional  background  appropriate  to  the  definite  con- 
ception. In  the  language  of  our  illustration,  we  may  say 
that  the  superior  nervous  centres  in  playing  upon  the  in- 
ferior ones,  brings  out  not  only  specific  chords  and  cadences 
of  feelings,  but,  in  so  doing,  arouse  reverberating  echoes  of 
all  kindred  chords  and  cadences  that  have  been  struck  dur- 
ing an  immeasurable  past — producing  a  great  volume  of 
indefinite  tones  harmonizing  with  the  definite  tones.* 

•  Let  me  in  passing  remark  that  these  views  of  the  respective  functions 
of  the  nervous  centres,  make  intelligible  various  physiological  and  patholo- 


672  PHYSICAL  SYNTHESIS. 

§  248.  A  few  remarks  are  here  called  for  respecting  the 
tenets  of  the  phrenologists.  It  scarcely  needs  saying  that 
the  conception  above  elaborated,  implying  the  constant  co- 
operation of  all  the  leading  nervous  centres  in  every  thought 
and  emotion,  is  quite  at  variance  with  their  theory,  as 
presented  by  themselves.  But  it  may  be  necessary  to  point 
out  that  I  do  not  hence  infer  the  ahsohite  untruth  of  their 
theory. 

That  the  contemptuous  antagonism  they  have  met  with 
from  both  psychologists  and  physiologists  is  in  great  meas- 
ure deserved,  must  be  admitted.  They  have  put  forth  their 
body  of  doctrines  as  in  itself  a  complete  system  of  Psychol- 
ogy— naturally  repelling  by  this  absurdity  all  students  of 
mental  science.  At  best.  Phrenology  can  be  but  an  appen- 
dix to  Psychology  proper;  and  one  of  comparative  unim- 
portance, scientifically  considered.  That  those  who  have 
carefully  investigated  the  structure  and  functions  of  the 
nervous  system,  should  have  long  ago  turned  their  backs 
on  Phrenology,  is  also  not  to  be  wondered  at;  seeing  how 
extremely  loose  the  phrenologists  are  in  their  methods  of 
observation  and  reasoning,  and  how  obstinately  they  ignore 
the  adverse  evidence  furnished  by  experiment. 

Nevertheless,  it  seems  to  me  that  most  physiologists  have 
not  sufficiently  recognized  the  general  truth  of  which  Phre- 

gical  phenomena.  We  see  how  it  is  possible  for  the  cerebrum  and  cerebellum 
to  be  greatly  injured,  and  indeed  wholly  shorn  away,  without  destroying 
the  power  to  perform  the  simpler  acts  of  perception  and  co-ordination ;  just 
as  it  is  possible  for  the  mechanical  piano,  after  the  removal  of  all  its  tune- 
boards,  to  continue  responsive  to  the  hands  of  the  musician.  Again,  the 
medulla  being  the  seat  of  all  feelings,  whether  aroused  from  without  or 
from  within,  it  naturally  happens  that  its  undue  excitement,  in  whatever 
way  caused,  produces  through  the  vagus  nerve  like  effects  on  the  viscera 
— it  naturally  happens  that  sensations  intensely  painful  or  pleasurable, 
and  emotions  intensely  painful  or  pleasurable,  alike  cause  fainting,  and 
that  fainting  may  be  caused  even  by  intense  intellectual  action.  Simi- 
larly, it  becomes  comprehensible  why  the  medulla  is  so  generally  the  sea", 
of  chronic  nervous  disorders ;  whether  the  excess  from  which  they  aris« 
be  sensational,  emotional,  or  intelleotuaL 


FUNCTIONS  AS  RELATED  TO  THESE  STRUCTURES.    5Y3 

nology  is  an  adumbration.  Whoever  calmly  considers  the 
question,  cannot  long  resist  the  conviction  that  different 
parts  of  the  cerebrum  must,  m  soTne  way  or  other,  subserve 
different  kinds  of  mental  action.  Localization  of  function  is 
the  law  of  all  organization  whatever;  and  it  would  be 
marvellous  were  there  here  an  exception.  If  it  be  admitted 
that  the  cerebral  hemispheres  are  the  seats  of  the  higher 
psychical  activities;  if  it  be  admitted  that  among  these 
higher  psychical  activities  there  are  distinctions  of  kind, 
which,  though  not  definite,  are  yet  practically  recognizable ; 
it  cannot  be  denied,  without  going  in  direct  opposition  to 
established  physiological  principles,  that  these  more  or  less 
distinct  kinds  of  psychical  activity  must  be  carried  on  in 
more  or  less  distinct  parts  of  the  cerebral  hemispheres.  To 
question  this  is  to  ignore  the  truths  of  nerve-physiology  as 
well  as  those  of  physiology  in  general.  It  is  proved,  experi- 
mentally, that  every  bundle  of  nerve-fibres  and  every  gan- 
glion has  a  special  duty;  and  that  each  part  of  every  such 
bundle  and  every  such  ganglion  has  a  duty  still  more  spe- 
cial. Can  it  be,  then,  that  in  the  great  hemispherical  gan- 
glia alone,  this  specialization  of  duty  does  not  hold?  That 
there  are  no  conspicuous  divisions  here  is  true ;  but  it  is  also 
true  in  other  cases  where  there  are  undeniable  differences  of 
function — instance  the  spinal  cord,  or  one  of  the  great 
nerve-bundles.  Just  as  there  are  aggregated  together  in  a 
sciatic  nerve  an  immense  number  of  fibres,  each  of  which 
has  a  particular  office  referring  to  some  one  part  of  the  leg, 
but  all  of  which  have  for  their  joint  duty  the  management 
of  the  leg  as  a  whole ;  so,  in  any  one  region  of  the  cerebrum, 
each  fibre  may  be  concluded  to  have  some  particular  office 
which,  in  common  with  the  particular  offices  of  many  neigh- 
bouring fibres,  is  merged  in  some  general  office  fulfilled  by 
that  region  of  the  cerebrum.  Any  other  hypothesis  seems 
to  me,  on  the  face  of  it,  untenable.  Either  there  is  some 
arrangement,  some  organization,  in  the  cerebrum,  or  there 
is  none.     If  there  is  no  organization,  the  cerebri  m  '^  r. 


574  PHYSICAL  SYNTHESIS. 

chaotic  mass  of  fibres,  incapable  of  performing  any  orderly 
action.  If  there  is  some  organization,  it  must  consist  in  that 
same  "  physiological  division  of  labour  "  in  which  all  or- 
ganization consists;  and  there  is  no  division  of  labour, 
physiological  or  other,  but  what  involves  the  concentration 
of  special  kinds  of  activity  in  special  places. 

But  to  coincide  with  the  doctrine  of  the  phrenologists  in 
its  most  abstract  shape,  is  by  no  means  to  coincide  with  their 
concrete  embodiments  of  it.  Indeed,  the  crudity  of  their 
philosophy  is  such  as  may  well  make  men  who  to  some  ex- 
tent agree  with  them,  refrain  from  avowal  of  their  agree- 
ment: more  especially  when  they  are  met  by  so  great  an 
unwillingness  to  listen  to  any  criticisms  on  the  detailed 
scheme  rashly  promulgated  as  finally  settled. 

Among  fundamental  objections  to  their  views,  the  first  to 
be  set  down  is  that  they  are  unwarranted  in  assuming  precise 
demarkations  of  the  faculties.  The  only  localization  which 
the  necessities  of  the  case  imply,  is  one  of  a  comparatively 
vague  kind — one  which  does  not  suppose  specific  limits,  but 
an  insensible  shading-off.  And  this  is  just  the  conclusion 
to  which  all  the  preceding  investigations  point.  For  as  we 
have  seen  that  every  mental  faculty,  rightly  understood,  is 
an  internal  plexus  of  nervous  connexions  corresponding 
to  some  plexus  of  relations  among  external  pheno- 
mena that  are  habitually  experienced;  and  as  the  different 
plexuses  of  external  relations,  in  proportion  as  they 
become  complicated,  become  less  definite  in  their  dis- 
tinctions, so  that  when  we  reach  those  extremely  involved 
ones  to  which  the  higher  faculties  respond  there  arises  a 
great  overlapping  and  entanglement  of  different  plexuses; 
it  follows  that  the  answering  internal  plexuses  must  be  fused 
together — it  must  be  as  impossible  to  demarkate  the  internal 
nervous  aggregations,  as  it  is  to  demarkate  the  aggregations 
of  external  things  and  actions. 

Moreover,  I  believe  the  phrenologists  to  be  wrong  in  as- 
suming that  there  is  something  specific  and  unalterable  in 


FUNCTIONS  AS  RELATED  TO  THESE  STRUCTURES.    575 

the  natures  of  the  various  faculties.  Responding,  as  facul- 
ties do,  to  particular  assemblages  of  phenomena  habitually 
surrounding  any  race  of  organisms,  they  are  only  so  far  fixed 
and  specific  as  these  are  fixed  and  specific.  A  permanent 
alteration  in  one  of  these  assemblages,  would  in  time  estab- 
lish a  modified  feeling  adapted  to  the  modified  assemblage. 
A  habit — say  of  sitting  in  a  particular  place  in  a  particular 
room,  ending  in  being  uncomfortable  elsewhere — is  nothing 
but  an  incipient  emotion  answering  to  that  group  of  outer 
relations;  and  if  all  the  successors  of  the  person  having 
this  habit  were  constantly  placed  in  the  same  relations, 
the  incipient  emotion  would  become  an  established  emotion. 
So  little  specific  are  the  faculties  that  no  one  of  them  is 
quite  of  the  same  quality  in  different  persons.  Each  mental 
power  is  variable  to  as  great  an  extent  as  each  feature  is 
variable. 

Yet  further,  the  current  impression  of  phrenologists  seems 
to  be  that  the  different  parts  of  the  cerebrum  in  which  they 
locate  different  faculties,  are  of  themselves  competent  to  pro- 
duce the  manifestations  implied  by  the  names  they  bear. 
The  portion  of  brain  marked  "  acquisitiveness,"  is  supposed 
to  be  alone  concerned  in  producing  the  desire  of  possession. 
But  it  is  a  corollary  from  foregoing  arguments  that  this  de- 
sire includes  a  number  of  minor  desires  elsewhere  located. 
As  every  more  complex  aggregation  of  psychical  states,  is 
evolved  by  the  union  of  simpler  aggregations  previously 
established — results  from  the  co-ordination  and  consolida- 
tion of  these;  it  follows  that  that  which  becomes  more  espe- 
cially the  seat  of  this  more  complex  aggregation,  or  higher 
feeling,  is  simply  the  centre  of  co-ordination  by  which  all 
the  simpler  aggregations  are  brought  into  relation.  Hence, 
that  particular  portion  of  the  cerebrum  in  which  a  particular 
faculty  is  said  to  be  located,  must  be  regarded  as  an  agency 
by  which  the  various  actions  going  on  in  many  other  parts  of 
the  cerebrum  are  combined  in  a  particular  way.  The  brain, 
active  throughout,  evolves  under  the  co-ordinating  plexus 
38 


5Y6  PHYSICAL  SYNTHESIS. 

that  is  for  the  time  dominant,  an  aggregate  of  feelings 
that  is  various  in  quality  according  to  the  proportions  and 
arrangements  of  its  components;  just  as  out  of  the  same 
orchestra,  with  its  many  instruments  going  from  moment 
to  moment,  are  drawn  combinations  of  sounds  now  grave, 
now  gay,  now  martial,  now  pathetic,  according  to  the  way 
in  which  the  actions  of  its  parts  are  co-ordinated  by  the  com- 
poser's score. 

Saying  nothing  of  many  minor  objections  to  the  phreno- 
logical doctrine,  we  conclude  that  however  defensible  may 
be  the  hypothesis  of  a  localization  of  faculties,  when  pre- 
sented under  an  abstract  form,  it  is  quite  indefensible  under 
the  form  given  to  it  by  phrenologists.* 

•  In  the  first  edition  of  The  Principles  of  Psychology,  the  substance 
of  this  section  was  contained  in  Part  IV. — forming  the  conclusion  to  the 
chapter  on  "  The  Feelings," 


CHAPTEK  Vn. 

PSYCHICAL   LAWS   AS   THUS   INTERPRETED. 

§  249.  The  final  stage  of  the  synthetic  argument  has  at 
length  been  reached.  The  task  now  before  us  is  to  com- 
pare the  deductions  made  in  foregoing  chapters  from  a 
physical  principle,  with  the  inductively-established  laws  of 
mental  action,  and  to  see  if  the  two  correspond. 

It  was  pointed  out  in  §  222  that  the  «jw«Wlaw  of  intel- 
ligence would  be  fulfilled,  and  the  growth  of  intelligence 
would  be  explained,  if  it  could  be  shown  "  that  when  a 
wave  of  molecular  transformation  passes  through  a  nervous 
structure,  there  is  wrought  in  the  structure  a  modification 
such  that,  other  things  equal,  a  subsequent  like  wave  passes 
through  this  structure  with  greater  facility  than  its  prede- 
cessor." It  was  thereafter  inferred  from  established  mecha- 
nical principles,  that  a  structural  change  of  this  kind  will 
occur.  And  we  have  since  occupied  ourselves  in  tracing  up 
nervous  evolution  as  an  accumulated  result  of  such  changes. 

All  that  remains  is  to  observe  whether  the  facts  of  daily 
experience  are  similarly  interpretable — whether  the  hypo- 
thesis is  further  verified  by  the  agreement  of  its  corollaries 
with  the  generalizations  of  psychologists  and  with  popu- 
larly-recognized truths. 

§  250.  The  congruity  between  the  established  laws  of 
association  and  the  several  implications  of  the  physical  prin- 
ciple laid  down,  is  conspicuous. 

577 


578  PHYSICAL  SYNTHESIS. 

Experience  continually  shows  us  that,  other  things  equal, 
the  connexion  formed  between  two  feelings  or  ideas  that 
occur  together  or  in  succession,  is  strong  when  they  are 
vivid  and  feeble  when  they  are  faint.  This  truth  is  de- 
ducible  from  the  hypothesis.  In  proportion  to  the  strength 
of  the  discharge  passing  through  a  line  of  unsymmetrically 
placed  molecules,  will  be  the  amount  of  force  expended  in 
bringing  them  towards  symmetrical  arrangement:  so  en- 
abling them  to  convey  the  next  discharge  with  less  resist- 
ance. Whence  it  follows  that  the  more  vivid  the  connected 
feelings  the  more  readily  will  recurrence  of  the  one  cause 
recurrence  of  the  other — the  closer  will  be  the  association 
between  them. 

It  is  a  proposition  equally  familiar,  that  repetition  of  the 
relation  between  two  states  of  consciousness,  presentative 
or  representative,  strengthens  their  union.  The  more  fre- 
quently transition  from  the  first  to  the  second  occurs, 
the  more  coherent  they  become — the  more  easily  does 
the  antecedent  arouse  the  consequent.  This,  too,  is 
a  corollary  from  our  hypothesis.  For  the  implication 
of  the  argument  set  forth  in  §  224  is,  that  of  the  molecular 
motion  discharged  along  a  line  of  isomerically-changing 
molecules  unsymmetrically  arranged,  part  is  passed  on 
by  each  molecule  to  the  next,  while  part  is  absorbed  in 
bringing  it  towards  symmetrical  relations  with  its  neigh- 
bours. Hence  of  a  subsequent  like  discharge,  more  will  be 
passed  on  and  less  will  be  absorbed  in  this  re-arrangement: 
there  will  be  a  diminished  resistance  to  the  excitement  of 
the  one  nervous  state  by  the  other;  and  the  correlative  feel- 
ings will  become  more  coherent. 

A  further  fact  finds  here,  too,  its  explanation.  In  the 
process  of  connecting  mental  states,  it  is  observable  that  the  i 
earlier  repetitions  of  the  relation  between  them  have  greater  j 
effects  than  the  later  repetitions.  For  some  time,  recurrences 
of  a  sequence  go  on  appreciably  increasing  the  readiness 
with  which  the  antecedent  excites  the  consequent;  but  the 


PSYCHICAL  LAWS  AS  THUS  INTERPRETED.         579 

increase  gradually  becomes  less  and  less  appreciable.  The 
saying  that  practice  makes  perfect  is  but  approximately 
true.  The  proficiency  gained  by  practice  (as  we  see  plainly 
in  games  of  skill  which  furnish  definite  measures  of  profi- 
ciency) augments  at  first  rapidly,  then  less  rapidly,  and  at 
length  scarcely  at  all:  each  individual  reaches  a  limit  be- 
yond which  repetitions  of  the  nervous  changes  and  con- 
comitant successions  of  feelings  bring  no  sensible  improve- 
ment. The  physical  cause  is  this.  When  a  wave  of  molecu- 
lar motion  passes  through  a  line  of  molecules  that  are  greatly 
out  of  symmetrical  arrangement,  much  of  it  is  absorbed  in 
turning  them  toward  symmetrical  arrangement.  As  they 
approach  nearer  and  nearer  to  symmetrical  arrangement, 
more  and  more  of  the  wave  passes  on^ — less  and  less  is  thus 
absorbed.  But  to  say  that  each  molecule  offers  a  diminish- 
ing resistance  to  the  transfer  of  the  wave,  is  to  say  that  there 
is  a  diminution  of  the  force  which  tends  to  bring  it  into  polar 
relations  with  its  neighbours.  And  since  the  molecule  has 
inertia  and  is  also  restrained  by  the  actions  of  surrounding 
molecules,  the  force  available  for  altering  its  position  bears 
a  continually-decreasing  ratio  to  the  forces  that  maintain  its 
position ;  until  at  length  the  effect  of  this  re-adjusting  force 
becomes  insensible. 

§  251.  The  laws  of  more  complex  mental  changes  are 
similarly  interpretable.  I  refer  to  the  phenomena  of  habit, 
considered  under  those  involved  forms  in  which  the  emo- 
tions play  a  leading  part. 

It  is  a  familiar  fact  that  a  course  of  action,  or  a  mode  of 
life,  originally  repugnant,  usually,  in  course  of  time,  gets 
less  repugnant — eventually  becoming  indifferent  or  even 
agreeable.  Physiologically  considered,  a  disagreeable  course 
of  action  is  one  in  which  compound  feelings  have  to  issue  in 
compound  actions,  through  complex  nervous  structures  that 
offer  considerable  resistance.  The  result  is  that  an  extra 
quantity  of  feeling  (commonly  the  fear  of  pain  that  may 


580  PHYSICAL  SYNTHESIS. 

result  from  non-performance)  has  to  be  evoked  before  the 
actions  can  be  excited.  But  since  the  complex  discharges 
through  these  complex  channels  render  them  gradually  more 
permeable,  it  results  that  the  quantity  of  disagreeable  repre- 
sentation of  pain  required  to  excite  the  actions,  decreases; 
and  at  length  the  permeability  of  these  channels  may  be- 
come such  that  the  spontaneous  flow  of  ordinary  feelings 
suffices — nay,  these  channels  may  become  needful  for  the  due 
discharge  of  ordinary  feelings;  which  otherwise  discharge 
themselves  in  the  purposeless  activity  we  call  restlessness. 

Where  the  inherited  organization  already  affords  channels 
for  the  easy  discharge  of  special  feelings  in  special  actions 
— that  is,  where  there  pre-exists  an  emotion  prompting  a 
particular  kind  of  conduct,  we  see  that  often-repeated 
passage  of  such  emotion  into  such  conduct  renders  less  and 
less  resistible  its  tendency  thus  to  pass.  The  more  fre- 
quently the  impulse  is  yielded  to,  the  more  difficult  becomes 
restraint  of  it;  until  at  length  the  act  it  excites  follows  the 
feeblest  solicitation  of  the  impulse.  Truths  of  this  class, 
continually  illustrated  among  the  lower  impulses  and 
illustrated  as  clearly,  though  less  frequently,  among  the 
higher  impulses,  are  corollaries  from  the  same  general 
principle. 

§  252.  From  this  general  principle,  too,  may  be  derived 
an  explanation  of  certain  leading  traits  of  developed  intelli- 
gence, as  distinguished  from  intelligence  which  is  unde- 
veloped. 

We  have  seen  how  from  the  process  of  nervous  evolution 
a.s  physically  caused,  it  follows  that  actions  become  less 
automatic  as  they  become  more  complex.  When  but  a 
single  afferent  nerve  runs  to  a  single  ganglion,  whence 
issues  a  solitary  efferent  nerve  to  a  solitary  muscle,  there 
can  be  no  discrimination  and  no  variety  of  action.  When 
the  reflex  action  becomes  compound,  responding  to  more 
numerous  combined  outer  stimuli  by  more, numerous  com- 


PSYCHICAL  LAWS  AS  THUS  INTERPRETED.        581 

bined  inner  actions,  the  change  is  in  itself  towards  discrimi- 
nation and  variety  of  action,  and  opens  the  way  to  further 
changes  in  the  same  direction.  For,  as  indicated  in  §§  235, 
237,  in  proportion  as  reflex  actions  increase  in  complica- 
tion, there  arise  more  numerous  hesitations,  both  of  the  kind 
that  habitually  precede  each  established  reflex  action,  and 
of  the  kind  that  accompany  the  partially-formed  reflex 
actions.  Similarly,  as  we  ascend  to  intelligences  in  which 
highly-involved  impressions  initiate  highly-involved  kinds 
of  conduct,  the  automatic  and  instinctive  adjustments  bear 
a  continually-decreasing  ratio  to  the  mass  of  adjustments — 
there  is  an  increasing  proportion  of  actions  that  take  place 
with  deliberation  and  consciousness,  as  well  as  an  increase 
in  the  amount  of  deliberation  and  degree  of  conscious- 
ness. What  is  the  implication  of  this  law  as  apply- 
ing to  different  grades  of  men?  It  is  that  those  having 
well-developed  nervous  systems  will  display  a  relatively- 
marked  premeditation — an  habitual  representation  of  more 
various  possibilities  of  cause,  and  conduct,  and  consequence 
— a  greater  tendency  to  suspense  of  judgments  and  an  easier 
modification  of  judgments  that  have  been  formed.  Those 
having  nervous  systems  less  developed,  with  fewer  and 
simpler  sets  of  connexions  among  their  plexuses,  will 
show  less  of  hesitation — will  be  prone  to  premature  conclu- 
sions that  are  difficult  to  change.  Unlikenesses  of  this 
kind  appear  when  we  contrast  the  larger  brained  races 
with  the  smaller  brained  races — when  from  the  compara- 
tively-judicial intellect  of  the  civilized  man  we  pass  to 
the  intellect  of  the  uncivilized  man,  sudden  in  its  infer- 
ences, incapable  of  balancing  evidence,  and  adhering  obsti- 
nately to  first  impressions.  And  we  may  observe  a  differ- 
ence similar  in  kind  but  smaller  in  degree  between  the 
modes  of  thought  of  men  and  women;  for  women  are  the 
more  quick  to  draw  conclusions,  and  retain  more  pertina- 
ciously the  beliefs  once  formed. 

Of  kindred  meaning  is  the  difference  between  the  cul- 


582  PHYSICAL  SYNTHESIS. 

tured  and  tlie  uncultured  of  the  same  race  and  of  the  same 
sex.  The  education  of  the  individual  (using  the  word  edu- 
cation in  its  proper  sense)  is  but  a  carrying  further  of  that 
process  by  which  intelligence  in  general  has  been  evolved. 
It  consists  in  extending  and  making  better  the  correspond- 
ence of  inner  relations  to  outer  relations — that  is,  in  organ- 
izing the  combinations  of  ideas  into  agreement  with  the 
combinations  of  phenomena.  And  its  physical  concomi- 
tant must  be  the  formation  in  the  individual  of  more  mul- 
titudinous and  more  involved  connexions  of  plexuses.  The 
brain  of  the  uncultivated  man  as  compared  to  that  of  the 
cultivated  man,  must  be  one  in  which  the  routes  taken  by 
nervous  discharges  are  less  numerous,  less  involved,  less 
varied  in  the  resistances  they  offer — one,  therefore,  in  which 
the  number  of  ideas  that  can  follow  a  given  antecedent  is 
smaller,  and  the  degrees  of  strength  with  which  they  can 
present  themselves  are  fewer — one,  therefore,  in  which  the 
possibilities  of  thought  are  more  limited,  and  the  balancing 
between  alternative  conclusions  less  easy.  This  is  the  reason 
that  ignorant  people  generalize  hastily,  and  adhere  obsti- 
nately to  the  erroneous  conclusions  based  on  their  scanty 
experiences;  while  the  highly-instructed  man  is  able  to 
keep  his  judgment  undecided — waits  for  more  evidence, 
contemplates  other  possible  inferences  than  the  one  he  is 
inclined  to  draw,  and  is  ready  to  abandon  or  qualify  his 
conviction  when  he  discovers  facts  at  variance  with  it. 

Without  going  further  into  detail,  it  will  be  obvious  that 
these,  and  other  traits  of  progressing  intelligence,  harmO' 
nize  with  the  principle  that  lines  of  nervous  communication  ^ 
are  formed  by  the  passage  of  waves  of  molecular  motion,] 
and  become  the  more  permeable  the  more  frequently  such] 
waves  are  repeated. 

§  253.  Mental  evolution  in  its  higher  stages  shows  us  a| 
further  peculiarity  which  has  the  same  general  nature  and] 
admits  of  the  same  general  interpretation.    I  refer  to  that! 


PSYCHICAL   LAWS  AS  THUS  INTERPRETED.         583 

brought  out  by  comparing  the  emotional  characters  of  infe- 
rior and  superior  minds. 

We  have  seen  that  beginning  with  simple  feelings,  rising 
to  clusters  of  feelings,  afterwards  to  clusters  of  these  clus- 
ters, and  so  on  to  aggregates  more  massive  and  more  hetero- 
geneous, the  nervous  structures  which  are  their  seats  advance 
in  complication  by  the  super-posing  of  new  plexuses  whereby 
pre-existing  plexuses  have  their  actions  co-ordinated.  The 
implication  is  that  the  earlier  and  simpler  feelings,  being 
the  more  directly  intermediate  between  special  combina- 
tions of  external  stimuli  and  special  combinations  of  adapted 
actions,  are  the  more  independent  of  one  another  and  the 
more  liable  to  act  separately;  while  as  fast  as  there  are 
evolved  those  later  feelings  into  which  the  simpler  ones 
enter  as  components,  there  is  a  decreased  tendency  for  the 
simpler  ones  to  act  separately.  In  other  words,  the  devel- 
opment of  the  highest  plexuses  is  the  development  of  ap- 
pliances by  which  simpler  plexuses  of  different  kinds  are 
simultaneously  excited,  and  the  different  modes  of  action 
which  they  prompt,  simultaneously  made  nascent.  It  re- 
sults, then,  that  along  with  advancing  evolution  of  the  feel- 
ings there  will  go  a  diminution  of  fitfulness  and  uncertainty 
of  conduct.  An  emotional  nature  not  well  developed  will 
be  relatively  impulsive — the  liability  will  be  for  each  passion 
to  display  itself  quickly  and  strongly,  without  check  from 
the  rest,  and  to  exhaust  itself  very  soon.  While,  along  with 
high  emotional  development  there  will  be  little  liability  to 
sudden  outbursts  of  feeling — the  simultaneous  rise  of  one 
or  more  counter-feelings  proper  to  the  circumstances,  will  in 
most  cases  retard  or  qualify  the  manifestations;  but  the 
conduct  eventually  decided  on,  prompted  by  a  greater  num- 
ber of  feelings  severally  less  excited,  will  be  more  persist- 
entj  Here,  as  before,  the  contrast  between  the  higher  and 
the  lower  races  of  men  furnishes  an  illustration ;  and  here, 
too,  as  before,  a  further  but  less  marked  illustration  is  fur- 
nished by  the  contrast  between  men  and  women. 


584  PHYSICAL  SYNTHESIS. 

Indeed,  under  this,  as  under  other  aspects,  mental  evolu- 
tion, both  intellectual  and  emotional,  may  be  measured  by 
the  degree  of  remoteness  from  primitive  reflex  action.  The 
formation  of  sudden,  irreversible  conclusions  on  the  slender- 
est evidence,  is  less  distant  from  reflex  action  than  is  the 
formation  of  deliberate  and  modifiable  conclusions  after 
much  evidence  has  been  collected.  And,  similarly,  the 
quick  passage  of  simple  emotions  into  the  particular  kinds 
of  conduct  they  prompt,  is  less  distant  from  reflex  action 
than  is  the  comparatively-hesitating  passage  of  compound 
emotions  into  kinds  of  conduct  determined  by  the  joint  insti- 
gation of  their  components. 


CHAPTEK  Yin. 

EVIDENCE    FROM    NORMAL   VARIATIONS. 

§  254.  Thus  far  the  evolution  of  nervous  structures,  and 
of  their  functions,  has  been  considered  without  reference 
to  the  varying  physiological  conditions  that  affect  the  pro- 
cess from  moment  to  moment,  as  well  as  from  generation  to 
generation.  We  have  spoken  as  though  the  physical  actions 
by  which  nervous  channels  are  opened  and  made  more  per- 
meable, equally  with  those  by  which  the  discharges  along 
established  channels  produce  their  respective  effects,  are 
actions  always  alike  in  kind  and  degree  if  the  stimuli  and 
the  structures  are  alike  in  kind  and  degree.  But  this  is  not 
the  case.  Here  we  must  take  note  of  several  circumstances, 
general  and  local,  which  modify  the  influence  of  the  same 
outer  agent  on  the  same  inner  part;  and  observe  the  cor- 
respondence between  the  variations  of  physical  effect  and 
the  accompanying  variations  of  psychical  effect. 

The  better  to  follow  in  thought  the  production  of  these 

variations,  let  us  carry  further  a  comparison  before  made. 

When  describing  how  discharges  of  molecular  motion  go 

along  lines  of  least  resistance,  and  by  recurring  render  them 

lines  of  less  resistance,  it  was  pointed  out  that  in  this  respect 

there  is  an  analogy  between  the  flow  of  molecular  motion 

and  the  flow  of  a  liquid ;  for  a  stream,  in  proportion  as  it  is 

strong  and  continued,  cuts  for  itself  a  large  and  definite 

channel  (§  224).     That  the  transfer  of  molecular  motion 

585 


586  PHYSICAL  SYNTHESIS. 

may  be  properly  thus  paralleled,  we  see  in  the  case  of  those 
forms  of  molecular  motion  known  as  heat  and  electricity; 
the  conduction  of  which  through  solid  bodies,  is  compared  to 
a  flow  that  takes  place  more  easily  through  some  substances 
than  through  others,  and  which,  in  bodies  having  polarized 
molecules,  passes  with  less  resistance  in  some  directions  than 
in  others.*  Reverting,  then,  to  the  common  hypo- 

thesis of  a  nervous  "  fluid  "  which  moves  in  nerve-"cur- 
rents  " — admitting  that  though  the  molecular  motion  which 
works  nervous  effects  is  not  a  fluid,  and  its  transfer  not  a 
current,  they  may  be  conveniently  dealt  with  as  though  they 
were;  let  us  consider  what  variations  of  special  results  will 
arise  from  incidental  variations  in  the  genesis  and  escape  of 
the  nervous  fluid.  Let  us  consider  the  nervous  system  as 
an  immensely  involved  set  of  channels,  some  wide  and  allow- 
ing an  easy  flow,  some  narrow  and  little  permeable — some 
communicating  with  one  another  by  large  openings  and 
others  by  openings  through  which  nothing  passes  except 
under  high  pressure ;  but  all  of  them  more  or  less  permeable 
and  more  or  less  connected.  Let  us  suppose  the  aggregate 
of  channels  so  constituted,  to  have  multitudinous  places 
through  which  its  contents  escape  and  multitudinous  places 
through  which  there  come  gushes  that  increase  its  contents; 
and  that  these  places  of  subtraction  and  addition  are  opened 
in  various  localities,  in  various  numbers,  and  in  various  de- 
grees— sometimes  the  subtractions  being  in  excess  and 
sometimes  the  additions.  Let  us  hence  infer  a  considerable 
variability  of  pressure  in  the  fluid  filling  these  ramifying 
channels — some  excessive  outflow  having  now  greatly  re- 
duced its  pressure,  and  the  large  inflows  having  now  raised 
its  pressure  above  the  usual  height.  And  lastly,  let  us  draw 
the  necessary  corollary  that  at  one  time  its  ebbing  streams 
pass  only  along  the  fully  open  and  the  more  permeable 
channels;  while  at  a  time  of  high  tide  its  streams  find  their 

♦  See  Prof.  Tyndall's  Beat  as  a  Mode  of  Motion,  Chapter  VII. 


EVIDENCE  PROM  NORMAL  VARIATIONS.  587 

ways  into  less  permeable  channels,  and,  aided  by  local  dis- 
turbances, escape  even  through  the  least  permeable  channels. 
Thus  symbolizing  the  physical  actions  to  which  the 
nervous  system  as  a  whole  is  exposed,  let  us  ask  how  its 
functions  will  be  affected  by  changes  of  physiological  con- 
ditions; and  how  the  accompanying  subjective  states  will 
be  modified. 

§  255.  Take  first  the  general  variations  which  are  seen 
on  contrasting  certain  mental  traits  of  youth  and  age. 

While  waste  and  repair  are  rapid,  the  ramifying  set  of 
channels  forming  the  nervous  system,  receives  such  a  large 
and  perpetual  influx  at  multitudinous  points,  that  it 
remains  well  filled  notwithstanding  the  large  efflux  con- 
tinuously going  on  at  multitudinous  points.  The  ingoing 
waves  of  molecular  motion  caused  by  peripheral  impres- 
sions, liberate  from  moment  to  moment,  in  the  sensory 
centres,  larger  waves,  or,  as  we  may  here  call  them,  quick 
gushes  of  the  "nervous  fluid;"  and  from  the  massive 
plexuses  of  the  higher  centres,  aroused  by  combinations  of 
disturbances  thus  arising,  there  are  added  to  the  contents 
of  the  nervous  system  still  more  powerful  and  continuous 
gushes.  Considering  first  the  physiological  results, 

we  see  that  the  channels  of  the  automatic  nervous  system  are 
filled  to  overflowing.  The  heart  pulsates  powerfully;  the 
alimentary  canal  works  vigorously;  the  lungs  are  well 
inflated ;  and  every  glandular  organ  receives  that  continuous 
discharge  which  keeps  up  the  peculiar  molecular  changes 
carried  on  in  it.  Meanwhile  the  voluntary  muscles,  receiv- 
ing their  share  of  this  abundant  efflux,  are  all  in  states  of 
partial  tension,  so  producing  attitudes  characteristic  of 
vigour;  and  they  are  severally  ready  to  contract  with 
great  force,  and  to  keep  up  their  contractions  for  long 
periods.  Among  accompanying  psychical  results, 

we  see  that  the  feelings  of  both  orders  are  vivid:  the 
sensations  are  distinct  and  the  emotions  lively.     We  see 


588  PHYSICAL  SYNTHESIS. 

also — and  this  it  is  which  more  especially  concerns  us  here 
— that  the  establishment  of  relations  between  feelings  is 
easy,  and  that  the  relations  when  established  are  relatively 
permanent.  Along  whatever  lines  of  nervous  communica- 
tion are  opened,  discharges  pass  that  are  strong  because  the 
pressure  is  great;  whence  results  a  great  amount  of  mole- 
cular re-arrangement  along  each  line  taken  by  a  discharge. 
A  subsequent  like  discharge  passes  with  comparative 
facility;  making  the  antecedent  state  easily  produce  the 
consequent  state — the  terms  of  the  relation  are  rendered 
coherent — the  memory  of  it  is  good. 

The  converse  connexion  of  phenomena  in  advanced  life, 
brings  out  more  clearly,  by  contrast,  the  law  we  are  contem- 
plating. In  common  with  the  body  at  large,  the  nervous 
system  is  supplied  with  poorer  blood  circulated  more 
slowly;  and  hence  when  wasted  it  is  less  rapidly  repaired. 
Its  channels,  therefore,  receive  from  moment  to  moment 
feebler  gushes  of  nervous  fluid;  the  general  pressure  is 
diminished;  and  all  the  various  overflowing  gushes  become 
less.  The   physiological   results   are    that   the 

actions  of  the  viscera  go  on  more  slowly.  Digestion  if  not 
positively  difiicult  is  a  sensible  tax;  and  the  propulsion  of 
blood  to  the  surface  is  no  longer  active  enough  to  contend 
with  any  great  loss  of  heat.  Throughout  the  muscular 
system,  too,  the  failing  nervous  discharge  is  seen;  alike  in 
the  chronic  relaxation  of  attitude  and  in  the  quick  following 
of  fatigue  upon  exertion.  Psychically,  this  state  is 

one  in  which  the  feelings  aroused  are  less  vivid  and  the  re- 
lations formed  between  them  less  coherent.  For  reading  a 
strong  light  is  required,  taste  and  smell  become  less  keen, 
hearing  grows  dull,  and  there  is  apathy  in  presence  of  cir- 
cumstances which  yield  strong  pleasurable  emotions  to  the 
young.  At  the  same  time  the  comparative  want  of  cohesioal 
between  impressions  is  shown  in  the  inability  to  recoiled 
the  names  of  persons,  the  times  of  occurrences,  &c.  And 
we  trace  out  the  successive  stages  of  failing  memory,  we  sed 


EVIDENCE  PROM  NORMAL  VARIATIONS.  589 

that  they  follow  the  order  inferable  from  the  hypothesis. 
Earliest  among  the  related  impressions  which  no  longer  so 
cohere  that  one  recalls  another,  are  those  made  by  daily 
trivialities — those  represented  in  the  nervous  system  by 
lines  through  which  feeble  discharges  have  but  once  passed. 
Interesting  statements  that  are  read,  and  passing  events  of 
considerable  importance,  presently  cease  to  be  recallable; 
though  like  statements  and  events  which  date  back  to  early 
life  are  still  recallable:  the  reason  being  that  the  channels 
of  nervous  communication  long  ago  made  by  the  strong 
gushes  answering  to  the  vivid  feelings  of  youth,  remain 
more  permeable  than  those  lately  made  by  the  feebler 
gushes  answering  to  the  fainter  feelings  of  age.  Passing 
over  many  gradations,  we  come  to  incoherences  of  thought 
in  which  the  place  now  inhabited  is  confounded  with 
places  inhabited  long  ago,  and  the  business  of  middle 
life  is  referred  to  as  though  transacted  yesterday — inco- 
herences implying  that  comparatively  permeable  channels 
are  now  so  far  deserted  that  the  discharges  along  them  do 
not  arouse  the  elements  of  these  familiar  ideas  in  their 
proper  relations.  And  eventually  we  reach  the  extreme 
state,  similarly  explicable,  in  which  even  members  of  the 
family,  who  have  been  companions  through  life,  cease  to  be 
recognized. 

§  256.  Let  us  consider  next  certain  general  psychical 
variations  that  accompany  differences  of  bodily  constitution. 
Some  of  these,  of  the  same  natures  as  the  foregoing,  we 
will  glance  at  before  passing  to  some  of  another  nature. 

In  consequence  of  specialities  of  inheritance,  specialities 
of  education,  and  specialities  of  mode  of  life,  high  mental 
manifestations  of  certain  kinds  may  go  along  with  weakness 
of  body.  But  classing  such  cases  as  abnormal  deviations 
from  that  constitutional  balance  which  is  needful  for  sur- 
vival through  future  generations;  and  limiting  our  atten- 
tion to  cases  where  no  monstrosity  has  been  produced  b^ 


590  PHYSICAL  SYNTHESIS. 

undue  forcing  of  the  individual  or  his  ancestors;  we  shall, 
I  think,  trace  a  connexion  between  abounding  physical  vig- 
our and  power  of  thinking  and  feeling,  as  well  as  between 
sluggishness  of  constitution  and  comparative  inertness,  in- 
tellectual and  emotional.  On  the  one  hand  we  have 
a  type  of  man  overflowing  with  muscular  energy  that  gives 
superiority  in  sports,  games,  and  feats  of  strength;  who  is 
keenly  alive  to  all  orders  of  gratifications,  sensational  and 
emotional;  who  acquires  knowledge  easily,  and  retains  it 
tenaciously;  and  who,  after  leaving  the  academic  life 
throughout  which  he  was  marked  by  these  united  traits, 
gains  distinction  partly  because  of  his  mental  activity  (not 
necessarily  of  a  high  order),  and  partly  because  of  the 
strength  of  constitution  which  enables  him  to  bear  intense 
and  prolonged  application.  On  the  other  hand  we 
have  a  type  of  man  whose  bodily  functions  are  slow;  who 
from  boyhood  upwards  cares  little  for  active  exercises; 
who  even  in  youth  is  indifferent  to  pleasures  which  others 
enjoy  greatly;  who  all  along  finds  learning  laborious;  and 
who,  in  after  life,  lapses  into  apathetic  idleness. 

These  contrasts  between  men  whose  nervous  systems 
work  under  high  pressure  and  under  low  pressure  re- 
spectively, I  draw  less  for  the  purpose  of  showing  their 
analogy  to  the  contrasts  between  the  young  and  the  old, 
than  for  the  purpose  of  drawing  attention  to  accompanying 
contrasts  of  another  kind.  We  have  seen  that  when  the 
pressure  throughout  the  nervous  system  is  high,  so  that  any 
disturbance  which  facilitates  escape  along  certain  channels 
is  followed  by  a  strong  gush  along  those  channels,  even 
though  they  are  not  very  permeable;  there  is  an  easy 
revival  of  old  connexions  of  ideas  and  a  formation  of 
new  connexions  that  are  very  coherent.  But  there  is 
much  more  than  this.  Interwoven  as  the  higher  nervous 
plexuses  are  in  such  intricate  ways,  in  correspondence 
with  the  intricate  interweaving  of  phenomena,  it  neces- 
sarily happens  that  a  wave  of  nervous  fluid  let  into  one  of 


EVIDENCE  PROM  NORMAL  VARIATIONS.  591 

them,  though  it  escapes  most  largely  along  certain  most 
permeable  channels,  escapes  in  part  along  other  channels 
that  are  less  permeable.  The  stronger  the  wave  the  greater 
the  number  of  these  supplementary  discharges;  and  the 
further  do  all  the  discharges,  larger  and  smaller,  make 
themselves  felt — rushing  out  into  more  multitudinous  and 
remote  ramifications  of  the  plexuses  they  enter.  Answer- 
ing to  this  physical  result  the  psychical  result  is  the  pro- 
duction of  ideas  that  are  more  numerous,  and  more  distinct, 
and  more  discursive.  The  area  of  consciousness  simul- 
taneously widens  and  brightens  as  the  pressure  of  the 
nervous  fluid  increases;  so  that  while  its  near  and  central 
elements  become  clearer,  elements  more  distant  from  the 
centre  come  into  view.  Between  the  two  types 

of  constitution  above  described,  we  see  such  mental  differ- 
ences as  are  hence  to  be  inferred.  The  man  whose  nervous 
system  works  under  high  pressure  shows  us  an  abundance 
of  ideas.  He  has  always  something  to  say;  and  instantly 
finds  words  fit  for  the  occasion.  All  the  proximate  bearings 
of  a  situation  or  an  event  quickly  occur  to  him;  and  out  of 
the  several  courses  which  almost  simultaneously  suggest 
themselves,  he  takes  the  appropriate  one.  He  thus  shows 
what  we  call  "  presence  of  mind ;  "  and  habitually  trusting 
with  success  to  the  fertility  of  his  resources,  he  has  courage 
in  facing  difficulties.  In  the  man  whose  nervous 

system  works  at  low  pressure,  thoughts  come  slowly  in  single 
file  instead  of  rapidly  in  a  column  formed  of  many  almost 
abreast.  The  various  possible  causes  and  consequences  of 
each  act  dawn  upon  him  gradually  one  by  one,  and  some 
of  them  not  at  all;  so  that  the  occasion  has  passed  before 
he  has  had  time  to  adjust  himself  to  it.  Finding  that  he  is 
consequently  unable  to  cope  with  men  who  have  "  their  wits 
about  them,"  he  leaves  the  crowded  thoroughfares  of  life 
and  takes  to  its  quiet  byeways. 

§  257.  That  general  physical  causes  entail  such  general 
89 


593  PHYSICAL  SYNTHESIS. 

psychical  differences,  we  see  not  only  on  contrasting  the 
minds  of  the  young  and  old  as  well  as  those  of  the  consti- 
tutionally vivacious  and  the  constitutionally  sluggish,  but 
also  on  contrasting  the  exalted  and  depressed  constitutional 
states  of  the  same  individual. 

Most  persons  have  had  experience  of  a  general  prostra- 
tion during  which  pleasures  are  accepted  apathetically, 
while  thinking  is  a  fatigue  and  the  effort  to  recollect  un- 
familiar things  repugnant;  and  along  with  this  diminished 
cohesion  of  ideas  there  is  a  diminished  number  of  them — 
instead  of  coming  in  a  continuous  crowd  they  come  as  a 
train  of  stragglers.  Conversely,  there  is  an  ex- 

ceptional invigoration,  often  traceable  to  some  favourable 
combination  of  conditions,  physical  and  social  (as  an  excur- 
sion along  with  intimate  friends)  in  which  the  mental  mani- 
festations are  unusually  vivid  and  abundant.  Every  thought 
is  clearly  and  quickly  seized;  apt  expressions  come  to  the 
mouth  without  hesitation;  illustrations  are  ready  on  the 
instant;  long-forgotten  anecdotes  recur;  and  out  of  the 
flood  of  ideas,  now  so  broad  and  swift,  there  are  readily 
formed  those  complex  combinations  of  likeness  and  differ- 
ence which  constitute  v<dt,  even  by  those  who  ordinarily  are 
not  witty. 

Clearly  these  opposite  deviations  from  the  mean  state, 
are,  like  the  others,  interpretable  as  caused  by  relatively 
low  pressure,  and  relatively  high  pressure,  throughout  the  - 
nervous  system. 

§  258.  One  other  variation  of  constitutional  state,  occur- j 
ring  daily,  presents  us  vnth  a  series  of  similar  effects  simi- 
larly produced. 

The  diminution  of  nervous  efflux  which,  reaching  a  cer-1 
tain  point,  shows  itself  in  an  increasing  quietude,  lapsing! 
into  sleep,  is  accompanied  by  a  descending  series  of  psychi-j 
cal  activities  conforming  to  the  general  principle  set  forth,| 
When  drowsiness  begins,  there  is  first  a  failure  of  the  feeble! 


EVIDENCE  FROM  NORMAL  VARIATIONS.  593 

and  more  complex  connexions  of  ideas,  as  well  as  a  de- 
creased quantity  of  ideas.  Thought  leaves  its  remoter  and 
less-beaten  tracks,  and  confines  its  excursions  to  the  more 
familiar  tracks — common-place  remarks  and  allusions  take 
the  place  of  wit  and  speculation.  Gradually  becoming  lim- 
ited to  a  still  narrower  range,  consciousness  is  by-and-bye 
made  up  of  little  else  than  those  almost  automatic  interpre- 
tations of  the  impressions  received  from  things  around 
which  constitute  recognitions  of  them.  And  at  length  when 
the  circulation  has  fallen  to  the  requisite  degree,  and  low 
tide  of  the  nervous  efilux  has  been  reached,  even  the  place 
and  the  persons  are  no  longer  known. 

The  dreams  that  occur  during  the  ensuing  sleep  present 
traits  of  like  meaning.  For  sleep-consciousness,  while  dif- 
fering from  waking  consciousness  mainly  in  being  independ- 
ent of,  and  uncorrected  by,  impressions  received  through 
the  senses,  differs  also  as  the  consciousness  of  the  old  does 
from  that  of  the  young,  or  that  of  the  inert  from  that  of  the 
vivacious.  Its  elements  are  less  coherent  and  less  abundant. 
An  ordinary  dream  is  so  faint  that  it  is  not  recallable  unless 
thought  of  just  after  waking;  and  then  only  a  few  of  its 
closing  scenes  are  recallable.  Even  these  are  not  coherent 
over  any  considerable  space;  but  through  some  accidental 
associations  each  new  act  or  occurrence  leads  off  into  quite 
another  series  of  acts  and  occurrences — there  is  a  perpetual 
wandering  away  from  what  was  just  before  thought  or  in- 
tended. Meanwhile,  the  narrowing  of  the  area  of  conscious- 
ness is  shown  in  the  absence  of  those  multitudinous  collateral 
thoughts  which  the  successive  scenes  are  fitted  to  arouse,  and 
in  the  consequent  acceptance  of  these  scenes  without  any 
sense  of  their  absurdity.  To  dream  of  flying  and  not  to 
suspect  any  illusion,  implies  that  thought  is  limited  to  a  nar- 
row train  of  simple  ideas;  and  that  there  are  not  aroused 
any  remembrances  of  those  antagonistic  experiences  and  of 
those  general  conceptions  framed  on  them,  which  are  im- 
plied by  scepticism  and  disbelief. 


594  PHYSICAL  SYNTHESIS. 

A  verification  meets  us  when  we  compare  the  dreams  ac- 
companying quiet  circulation  of  the  blood,  with  the  dreams 
accompanying  excited  circulation — either  through  the 
system  as  a  whole  or  through  the  brain  only.  For  under 
conditions  implying  a  higher  rate  of  molecular  change,  and 
consequently  of  nervous  discharge,  than  is  usual  during 
sleep,  the  dreams  become  both  more  vivid  and  more 
rational.  Many  acts  are  performed  in  succession  with  a 
view  to  some  desired  end;  and  the  earlier  members  of  the 
series  do  not  wholly  disappear  from  consciousness  as  the 
later  arise.  At  the  same  time  the  things  done,  the  means 
used,  the  difficulties  overcome,  are  less  incongruous  with 
waking  experience ;  because  of  the  greater  excursiveness  of 
thought,  and  the  consequent  accompaniment  of  criticism  on 
the  main  current  of  ideas. 

§  259.  Another  class  of  facts  offer  a  kindred  problem 
which  admits  of  a  kindred  solution.  I  refer  to  the  psychical 
variations  that  accompany  variations  not  in  the  state  of 
the  organism  as  a  whole  but  in  the  states  of  its  different 
parts. 

Given  a  nervous  system  in  any  constitutional  condition, 
what  will  happen  to  the  rest  if  one  portion  of  it  is  greatly 
excited?  Supposing  large  demands  to  be  made  on  the 
general  supply  of  nervous  fluid  by  a  powerful  discharge  in 
one  direction,  what  will  be  the  effects  on  discharges  in  other 
directions?  The  question  is  not  by  any  means  simple;  for 
ordinarily  a  nervous  action  is  accompanied  by  an  invigor- 
ated pulse  and  a  raised  respiration,  whence  it  results  that 
being  better  supplied  with  materials,  the  nervous  system 
generates  more  nervous  fluid.  Tip  to  a  certain  point,  there- 
fore, the  efflux  in  the  performance  of  some  one  kind  of  func- 
tion, has  the  effect  of  increasing  instead  of  diminishing  the 
general  efflux.  This  is  especially  the  case  with  those  modes 
of  nervous  expenditure  which  bring  with  them  increased 
excitements  of  the  sensations  and  emotions.     Nevertheless 


EVIDENCE  FROM  NORMAL  VARIATIONS.  596 

there  is  reason  to  suspect  that  some  effects  such  as  the  hy- 
pothesis implies  are  produced. 

When  muscular  effort  is  suddenly  pushed  to  excess,  say 
by  running  a  long  way  at  full  speed  or  by  climbing  a  moun- 
tain till  forced  to  desist  by  want  of  breath,  the  power  of 
thinking  is  appreciably  diminished.  Though  it  remains 
easy  to  unite  ideas  in  simple  combinations,  it  becomes  dif- 
ficult to  unite  them  in  complex  combinations — a  meta- 
physical question  demands  a  greater  mental  effort  than  can 
be  made.  The  emotions  undergo  a  like  enfeeblement — a 
temporary  apathy  ensues.  That  is  to  say,  an  excessive  ab- 
straction of  nervous  fluid  diminishes  so  much  the  general 
pressure  throughout  the  nervous  system,  that  no  dis- 
charges take  place  along  the  less  permeable  channels.  It  is 
true  that  the  aeration  of  the  blood  falls  in  arrear,  and  that 
diminished  genesis  of  nervous  fluid  thus  becomes  a  part- 
cause  of  these  effects;  but  we  shall  find  evidence  that 
it  is  only  a  part-cause.  For  the  alleged   con- 

nexion of  phenomena  is  quite  clearly  shown  on  passing 
to  those  nervous  discharges  which  have  not  increased 
excitements  of  feelings  as  their  concomitants.  When 
the  muscles  and  glands  of  the  alimentary  canal  are  at  work, 
the  heart  and  lungs  have  their  actions  raised ;  and  the  evo- 
lution of  nervous  energy  is  thereby  favoured.  But  their 
activity  brings  no  such  increased  evolution  of  nervous 
energy  as  does  that  of  the  locomotive  organs;  since  their 
activity  neither  yields  direct  sensations,  nor  incidentally 
entails  more  vivid  and  varied  perceptions  and  ideas,  with 
the  feelings  immediate  and  remote  which  they  imply. 
Consequently,  the  abstraction  of  nervous  fluid  by  the 
stomach  when  food  has  been  put  into  it,  is  an  almost  un- 
compensated deduction  from  the  general  supply  of  nervous 
fluid.  In  youth  the  mental  effect  is  not  much  felt;  but  in 
middle  life  and  after,  we  see  that  the  digestion  of  a  heavy 
meal  (at  least  in  the  absence  of  social  excitements)  entails 
such  a  diminution  of  pressure   throughout  the  nervous 


596  PHYSICAL  SYNTHESIS. 

system,  that  only  the  simple  and  coherent  relations  of  ideas 
are  formed  with  facility.  Processes  of  thought  which  imply 
discharges  through  involved  sets  of  channels  that  are  not 
very  permeable,  are  performed  with  difficulty.  There  is  a 
disinclination  to  mental  work  as  well  as  to  bodily  work;  and 
not  uncommonly,  the  overflow  so  far  fails  that  even  the 
simpler  relations  of  ideas  becoming  faint  and  confused, 
there  presently  follows  the  unconsciousness  of  sleep. 

§  260.  More  special  antagonisms,  akin  to  these  in  their 
natures  and  effects,  may  be  traced.  A  very  strong  emotion 
makes  such  a  draught  on  the  supply  of  nervous  fluid  as  to 
incapacitate  the  intellect  throughout  much  of  its  higher 
sphere.  Conceptions  that  come  in  the  lines  of  production 
and  discharge  of  the  emotion,  may  be  formed  with  facility 
and  vividness  (though  in  some  persons  even  these  fall  into 
confusion) ;  but  conceptions  unconnected  with  the  occasion, 
especially  of  kinds  that  are  abstract  or  involved,  become  for 
the  time  impossible.  There  seems  some  reason  to 

think  that,  conversely,  great  expenditure  of  energy  in  in- 
tense intellectual  action  is  accompanied  by  a  temporary 
diminution  of  emotional  sensibility.  It  may  be  suspected, 
too,  that  long-continued  intellectual  absorption,  of  a  kind 
which  has  little  or  no  emotional  excitement  for  its  accom- 
paniment, leads  to  a  permanent  enfeeblement  of  the  emo- 
tions. Indeed,  there  is  an  antagonism  of  different  faculties 
that  appears  to  necessitate  this — competing  with  one  an- 
other as  they  do  for  supplies  of  energy  and  materials  from 
the  same  general  stock. 

But  the  most  interesting  and  instructive  solution  belong- 
ing to  this  group,  is  that  afforded  of  the  aberrations  which 
emotions  produce  among  intellectual  processes.  When  we 
remember  that  the  plexuses  co-operating  in  any  involved 
mental  act,  are  made  up  of  multitudinous  channels  of  vari- 
ous degrees  of  permeability,  we  shall  see  that  the  mental  act 
can  be  properly  performed  only  when  the  discharges  through 


EVIDENCE  PROM  NORMAL  VARIATIONS.  597 

the  co-operating  plexuses  take  place  under  the  normal 
pressure.  As  before  shown,  the  least  permeable  plexuses 
are  the  first  to  become  functionally  inactive  as  the  pressure 
diminishes;  and  here  it  is  to  be  observed  that  for  the  same 
reason,  the  least  permeable  parts  of  each  plexus  will  as  the 
pressure  diminishes  have  their  discharges  appreciably  en- 
feebled before  the  more  permeable  parts.  But  right  mental 
adjustments,  implying  accurate  nervous  co-ordinations, 
depend  on  the  maintenance  of  due  proportions  among 
the  strengths  of  the  discharges;  and  anything  that 
alters  these  proportions  interferes  with  the  adjustments. 
Necessarily,  then,  a  strong  emotion  disturbs  the  intel- 
lectual balance.  Both  derangements  of  simple  percep- 
tions and  derangements  of  complex  judgments  show 
us  this.  Among  derangements  of  perceptions, 

I  may  refer  in  passing  to  those  which  great  fear 
produces — the  misinterpretation  of  visual  impressions  being 
in  this  state  of  mind  very  marked.  But  examples  that  are 
better,  because  the  effects  are  numerically  measurable,  occur 
among  those  who  play  games  of  skill.  If  when  about  to 
make  a  stroke  at  billiards  any  emotion  has  been  raised,  by 
the  presence  of  spectators  or  otherwise,  failure  is  very  apt 
to  result;  and  this  though  the  heart's  action  and  the  mus- 
cular tone  are  not  appreciably  affected.  The  cause  is 
clear.  Success  presupposes  great  exactness  in  the  ratios 
among  the  many  combined  contractions,  and  in  the  adapta- 
tion of  them  all  to  the  many  combined  impressions;  the 
ratios  among  which  have  also  to  be  exactly  appreciated. 
But  when  a  great  draught  of  nervous  fluid  to  the  parts  of 
the  nervous  system  occupied  in  an  emotion,  has  diminished 
the  pressure  under  which  these  sensory  and  motor  discharges 
are  made  through  the  co-operating  plexuses,  the  ratios 
among  the  actions  of  their  parts  are  so  far  changed  that  the 
co-ordination  becomes  imperfect.  That  among 

those  higher  intellectual  actions  we  class  as  judgments,  a 
like  disturbance  leads  to  a  like  derangement,  is  obvious. 


598  PHYSICAL  SYNTHESIS. 

Take  a  case.  To  decide  which  of  several  results  will  most 
likely  follow  some  step,  say  in  a  negociation,  implies  repre- 
sentations of  them  as  caused  by  complex  motives  and  cir- 
cumstances. These  several  results  rise  in  consciousness  with 
different  degrees  of  vividness  and  pertinacity;  and  to  be- 
lieve that  one  of  them  will  occur,  is  to  feel  that  this  one 
persists  in  consciousness  more  decidedly  than  the  others — 
the  greater  persistence  being  determined  by  some  prepon- 
derance of  kindred  experiences.  But  due  proportion  among 
the  tendencies  of  these  several  representations  to  arise  and 
continue,  depends  on  the  maintenance  of  the  normal  pres- 
sure or  nervous  fluid.  This  is  interfered  with  both  locally 
and  generally  by  strong  emotions.  In  the  first  place,  the 
particular  emotions  excited  in  reference  to  the  question  at 
issue,  perturb  the  judgment  by  increasing  the  discharge 
along  those  lines  of  representation  that  further  their  own 
excitement.  In  the  second  place,  these  particular  emotions, 
or  any  other  emotions,  perturb  the  judgment  by  affecting 
the  general  supply  of  nervous  fluid.  Under  the  high  tide 
which  extreme  elation  implies,  the  nervous  discharges  pass 
easily  along  the  less  permeable  channels,  and  the  feebler 
representations  are  raised  more  nearly  to  a  level  with 
stronger  ones,  so  that  discrimination  becomes  less  easy; 
whence  it  happens  that  improbable  results  of  a  desired  kind 
are  thought  probable.  While  under  a  state  of  depressed 
spirits,  judgment  fails  because  the  proportions  among  the 
nervous  discharges  are  interfered  with  in  an  opposite  way. 

§  261.  Fully  to  explain  these  last  derangements  of  judg- 
ment, however,  we  must  take  into  account  one  further  class 
of  variations  among  the  mental  activities.  In  entering  on 
this  class,  I  find  the  opportunity  of  redeeming  a  promise 
made  in  §  128;  where,  after  propounding  an  hypothesis 
respecting  the  natures  of  pleasures  and  pains,  it  was  hinted 
that  some  verification  would  be  furnished  at  a  later  stage  of 
the  argument.    We  saw  reason  to  think  "  that  while  Plea* 


EVIDENCE  PROM  NORMAL  VARIATIONS.  599 

sures  and  Pains  are  partly  constituted  of  those  local  and 
conspicuous  elements  of  feeling  directly  aroused  by  special 
stimuli,  they  are  largely,  if  not  mainly,  composed  of  sec- 
ondary elements  of  feeling  aroused  indirectly  by  diffused 
stimulation  of  the  nervous  system."  Here  we  have  to  con- 
sider what  further  reasons  for  thinking  this  are  now  appar- 
ent; and  what  further  solutions  they  introduce  us  to. 

That  every  special  pleasure  or  pain,  peripheral  or  central, 
does  produce  a  diffused  effect  is  clear.  I  do  not  mean  sim- 
ply that  this  is  a  corollary  from  the  foregoing  argument: 
I  mean  that  it  is  shown  experimentally.  Beyond  the  famil- 
iar fact  that  each  strong  sensation  or  emotion  affects  the 
action  of  the  heart,  we  have  the  fact  that  the  accompanying 
gush  of  nervous  fluid,  spreading  along  all  the  vaso-motor 
nerves,  changes  the  state  of  the  arteries  throughout  the 
whole  body.  Much  more  then  does  it  spread  through  those 
more  directly-related  parts  of  the  nervous  system  which  are 
seats  of  conscious  actions.  What  remains  here  to  inquire, 
then,  is  how  far  the  diffusion  is  specialized  according  to  the 
nature  of  the  feeling. 

In  tracing  out  the  genesis  of  emotions,  we  have  seen  that 
the  plexuses  which  co-ordinate  certain  clustered  impressions 
received  from  without,  with  the  combined  actions  appro- 
priate to  them,  are  necessarily  entangled  with  kindred 
plexuses  that  perform  kindred  co-ordinations.  We  have 
inferred  that  when  a  particular  plexus  is  excited,  it  im- 
mediately excites  the  mass  of  kindred  plexuses  with  which 
it  is  organized — the  result  being  that  the  feelings  proper  to 
this  mass  of  excited  plexuses  are  aroused,  and  in  their  mul- 
titudinous but  vague  aggregate,  constitute  the  accompany- 
ing emotion.  But  the  process  does  not  end  here.  This 
mass  of  plexuses  thus  excited  has  to  discharge  itself;  and 
the  question  now  to  be  asked  is — what  general  directions 
will  its  discharge  take,  and  what  will  be  the  general  na- 
ture of  the  produced  feelings?  The  answer  is  this.  Any 
excited  mass  of  plexuses  will  discharge  itself  into  the  masses 


600  PHYSICAL  SYNTHESIS. 

of  plexuses  with  which  it  has  most  in  common,  and  these 
into  others  similarly  related  to  them.  Now  the  plexuses 
in  which  one  kind  of  pleasurable  emotion  is  seated,  must 
have  much  in  common  with  the  plexuses  in  which  some 
other  kinds  of  pleasurable  emotions  are  seated ;  seeing  that 
the  external  plexuses  of  phenomena  to  which  they  refer 
have  much  in  common,  and  frequently  occur  together. 
The  smiles  and  tones  expressing  affection  are  approached 
by  those  expressing  approbation.  The  natural  language  of 
approbation  is  a  good  deal  like  the  natural  language  of 
benevolent  feeling.  The  manner  of  one  who  acts  kindly  to 
us  is  similar  to  the  manner  which  on  many  past  occasions 
has  preceded  and  accompanied  the  receipt  of  kindnesses, 
and  arouses  a  dim  consciousness  of  pleasures  that  are  fol- 
lowed— perhaps  of  agreeable  society,  perhaps  of  beautiful 
scenery,  perhaps  of  field  sports,  perhaps  of  all  these.  Evi- 
dently, then,  the  tendency  is  for  any  one  pleasurable  emo- 
tion to  discharge  itself  in  partially  exciting  pleasurable  emo- 
tions of  other  kinds;  so  that,  more  or  less  remotely,  all 
kinds  of  pleasures  come  to  be  ideally  presented  in  a  faint 
way.  But  since  besides  being  faint  they  are  so  multitudi- 
nous and  so  various  in  quality,  the  resulting  consciousness 
is  wholly  indefinite;  and  can  be  described  only  as  a  sense 
of  satisfaction  or  of  happiness.  Similarly  with  pains.  A 
particular  form  of  bodily  suffering  produced  by  internal 
derangement,  is  linked  by  near  resemblance  with  other 
forms  of  bodily  suffering  so  produced;  some  of  these  by 
their  localities  and  qualities  are  associated  in  consciousness 
with  the  pains  caused  by  external  cuts  and  bruises;  some 
of  these,  again,  are  connected  in  experience  with  the  im- 
pressions received  from  creatures  about  to  inflict  bodily 
injuries  on  us;  and,  of  such  impressions,  some  have  much  in 
common  with  those  received  from  men  who,  if  they  do  not 
threaten  bodily  injuries,  are  likely  to  do  something  that  will 
be  positively  or  negatively  painful  to  us  in  its  ultimate 
results.    Hence  a  special  pain,  or  rather  the  liberated  nerv- 


I 


EVIDENCE  FROM  NORMAL  VARIATIONS.  601 

ous  fluid  which  occurrence  of  it  implies,  discharging  itself 
along  lines  of  least  resistance,  partially  awakens  ideas  of 
associated  pains,  and  through  these  a  vaguer  consciousness 
of  pains  more  distantly  related,  till  by  its  ultimate  diffusion 
there  is  generated  an  obscure  feeling  of  discomfort  or  un- 
happiness.  And  hence  results  the  peculiarity  before  pointed 
out  (§  128)  that  the  total  consciousness  produced  by  a  par- 
ticular pleasure  (or  pain)  is  much  more  like  the  total  con- 
sciousness produced  by  other  particular  pleasures  (or  pains) 
than  is  the  initial  feeling  which  arouses  it  like  the  initial 
feelings  which  arouse  them. 

By  joining  with  this  conception  the  inferences  reached 
above,  it  becomes  possible  to  account  for  a  remaining  psychi- 
cal variation  of  a  seemingly  mysterious  nature.  How  does  it 
happen  that  a  certain  state  of  the  circulation,  or  of  the 
blood,  or  of  both,  causes  in  consciousness  a  predominance 
of  painful  ideas  and  a  vague  feeling  of  misery;  while  an- 
other state  of  the  circulation,  or  of  the  blood,  or  of  both, 
causes  a  predominance  of  pleasurable  ideas,  backed  by  a 
general  sense  of  content  or  even  of  exhilaration — and  this, 
too,  in  presence  of  the  same  circumstances?  We  find  no 
answer  in  any  recognized  laws  of  psychical  action;  nor  does 
any  answer  seem  deducible  from  established  principles  of 
nerve-physiology.  We  shall,  however,  find  an  answer  in 
that  synthesis  of  the  two  which  we  are  here  pursuing. 

The  diffusion  of  nervous  discharges  is  ordinarily  still 
wider  that  I  have  just  described  it  to  be — is  indeed,  as  at 
first  indicated,  universal.  When  the  initial  feelings  are  of 
a  pleasurable  kind,  the  diffusion  is  predomincmUy  in  the 
direction  of  associated  pleasurable  feelings;  and  conversely 
when  the  initial  feelings  are  of  a  painful  kind.  But  the 
diffusion  is  never  exclusively  in  either  direction,  because 
the  initial  feelings  of  either  kind  are  not  separable  from  ac- 
companying initial  feelings  which,  if  not  of  the  opposite 
kind,  are  still  of  a  kind  related  to  botb — namely,  the  in- 
different feelings.     The  sights  and  sounds,  the  sensations 


602  PHYSICAL  SYNTHESIS. 

of  touch  and  muscular  tension,  which  form  the  mass  of  our 
definite  consciousness  from  moment  to  moment,  are  con- 
nected in  experience  with  both  pleasures  and  pains;  and, 
unless  when  combined  in  particular  ways,  they  tend  to  arouse 
ideas  of  the  one  kind  as  much  as  ideas  of  the  other.  Ordi- 
narily, therefore,  that  background  of  consciousness  which 
constitutes  our  "  state  of  mind,"  as  distinguished  from  our 
passing  sensations,  perceptions,  and  ideas,  is  a  neutral  com- 
pound in  which  the  aggregate  of  perpetually-nascent  plea- 
surable feelings  is  fused  with  the  aggregate  of  perpetually- 
nascent  painful  feelings.  Equanimity  may  be  compared  to 
white  light,  which,  though  composed  of  numerous  colours 
is  colourless;  while  pleasurable  and  painful  moods  of  mind 
may  be  compared  to  the  modifications  of  light  that  result 
from  increasing  the  proportions  of  some  rays  or  decreasing 
the  proportions  of  others.  "  But  how,"  it  will  be  asked, 
"  does  this  interpretation  help  us  to  explain  the  genesis  of 
mental  depression  and  mental  elation?  Following  out  the 
simile,  may  it  not  be  said  that  as,  by  intensifying  combus- 
tion we  increase  the  brilliancy  of  the  light  without  altering 
its  quality,  so,  by  exalting  nervous  action  we  ought  simply 
to  increase  the  vividness  of  consciousness  without  altering  its 
quality?  "  The  reason  for  answering  in  the  negative  is  this. 
One  of  the  laws  of  association  is  that  the  stronger  the 
feelings  connected  in  experience  the  more  easily  does  the 
one  subsequently  recall  the  other;  and  the  physical  counter- 
part of  this  law  we  have  found  to  be  that  the  channel  taken 
by  any  nervous  discharge  is  made  the  more  permeable  in 
proportion  as  the  discharge  is  augmented.  Now  pains  in 
general  are  more  intense  than  pleasures  in  general.  Indeed, 
as  was  pointed  out  when  treating  of  the  two  (§  123),  pains 
of  the  positive  order  result  from  the  excesses  of  actions 
which  in  lower  degrees  are  pleasurable.  Other  things  being 
equal  then  (that  is  to  say  the  comparison  being  made  be- 
tween pleasures  and  pains  belonging  to  the  same  class  and 
that  have  been  similarly  repeated  in  experience)  the  idea  of 


EVIDENCE  FROM  NORMAL  VARIATIONS.  603 

a  pain  follows  its  antecedent  into  consciousness  more  readily 
than  the  idea  of  pleasure.  On  the  other  hand,  pleasures, 
though  less  intense,  are  n^ore  numerous,  and  are  more  vari- 
ously linked  with  other  elements  of  mind.  Setting  out  with 
the  mass  of  indifferent  feelings  forming  our  ordinary  per- 
ceptive consciousness,  we  may  say  that  in  the  "  state  of 
mind  "  which  is  its  background,  there  are  nascent  a  small 
number  of  painful  feelings  that  are  strong,  a  larger  number 
of  pleasurable  feelings  that  are  less  strong,  and  a  much 
larger  number  of  feelings  that  are  but  slightly  pleasurable : 
their  respective  cohesions  with  the  indifferent  feelings  be- 
coming, for  the  reasons  given,  less  strong  as  they  become 
more  numerous.  This  being  understood,  we  have 

now  only  to  ask  how  variations  of  pressure  throughout  the 
nervous  system  will  operate,  to  reach  the  solution  we  seek. 
When  this  pressure  is  high,  the  less  permeable  lines  of  dis- 
charge, answering  to  the  feebler  associations  among  our 
pleasurable  feelings,  are  filled  by  the  escaping  currents; 
and  the  aggregate  of  faintly-aroused  ideas  of  pleasure  grows 
in  extent  as  well  as  in  strength.  As  the  pressure  augments, 
this  diffused  consciousness  of  pleasure  bears  an  increasing 
ratio  to  the  diffused  consciousness  of  pain — so  producing  in 
its  ascending  degrees  a  sense  of  satisfaction,  of  happiness, 
of  joy  for  which  no  reason  can  be  given.  Contrari- 

wise, a  failing  genesis  of  nervous  fluid  being  followed  by 
cessation  of  the  efflux  along  the  least  permeable  lines  of  dis- 
charge, and  presently  by  its  cessation  along  lines  next  to 
these  in  their  small  permeability,  it  inevitably  happens  that 
as  the  pressure  goes  on  diminishing,  the  aggregate  of  faintly- 
aroused  pleasurable  feelings  bears  a  decreasing  ratio  to  the 
aggregate  of  faintly-aroused  painful  feelings.  And  when 
the  pressure  has  fallen  so  low  that  currents  pass  only  along 
very  permeable  lines,  it  results  that  the  diffused  conscious- 
ness, or  vague  background  to  our  definite  perceptions  and 
ideas,  comes  to  be  composed  mainly  of  the  aggregate  of 
faintly-aroused  painful  feelings — so  producing  gloom,  and 
crroundless  fear,  and  despair. 


CHAPTEK  IX. 

EVIDENCE   FBOM   ABNOBMAL   VAEIATIONS. 

§  262.  In  cause  and  consequence,  the  case  with  whicli 
the  last  chapter  closed  introduces  us  to  variations  of  the 
abnormal  class.  States  of  body  and  mind  like  that 
described,  passing  from  the  temporary  into  the  permanent, 
become  nervous  disorders;  presenting  us  with  many 
psychical  disturbances  accompanying  many  physical  dis- 
turbances. 

We  need  not  trace  over  again  in  these  cases  the  relation 
between  decreased  genesis  of  nervous  fluid  and  failure  of 
mental  power;  for  the  relation  is  substantially  the  same  as 
that  which  we  have  traced  in  the  aged  and  in  the  constitu- 
tionally sluggish — there  is  a  like  failure  of  memory,  a  like 
narrowing  of  the  area  of  consciousness  as  shown  in  dimin- 
ished excursiveness  of  thought,  and  a  like  want  of  readiness 
in  moments  of  emergency.  But  there  is  one  other  trait  of 
nervous  debility  not  hitherto  pointed  out,  on  which  a  few 
words  may  be  said.  I  refer  to  the  accompanying  change  of 
character,  or  modification  of  the  emotional  nature. 

Even  small  ebbings  of  the  nervous  fluid,  hardly  to  be 
called  abnormal,  produce  slight  modifications  of  this  kind; 
as  is  observable  in  children.  The  highest  co-ordinating 
plexuses  being  in  them  the  least  developed,  children  betray 
more  quickly  than  adults  any  defective  action  of  these 
plexuses;    and  they  habitually  do  this  when  the  general 

604 


EVIDENCE  FROM  ABNORMAL  VARIATIONS.         605 

nervous  pressure  is  below  par.  Sluggishness  of  the  ali- 
mentary canal,  implying  partial  failure  of  nutrition  and 
decreased  genesis  of  energy,  is  accompanied  by  fretfulness 
— by  a  display  of  the  lower  impulses  uncontrolled  by  the 
higher.  It  is,  however,  in  the  chronically  nervous, 

whose  blood,  deteriorated  in  quality  and  feebly  propelled, 
fails  to  keep  up  a  due  activity  of  molecular  change,  that  we 
see  this  connexion  of  phenomena  most  clearly.  The  irasci- 
bility of  persons  in  this  state  is  matter  of  common  remark; 
and  irascibility  implies  a  relative  inactivity  of  the  superior 
feelings.  It  results  when  a  sudden  discharge,  sent  by  a  pain 
or  annoyance  through  those  plexuses  which  adjust  the  con- 
duct to  painful  and  annoying  agencies,  is  unaccompanied 
by  a  discharge  through  those  plexuses  which  adjust  the 
conduct  to  many  circumstances  instead  of  a  single  circum- 
stance. That  deficient  genesis  of  nervous  fluid  accounts 
for  this  loss  of  emotional  balance,  is  a  corollary  from  all 
that  has  gone  before.  The  plexuses  which  co-ordinate  the 
defensive  and  destructive  activities,  and  in  which  are  seated 
the  accompanying  feelings  of  antagonism  and  anger,  are 
inherited  from  all  antecedent  races  of  creatures,  and  are 
therefore  well  organized — so  well  organized  that  the  child 
in  arms  shows  them  in  action.  But  the  plexuses  which,  by 
connecting  and  co-ordinating  a  variety  of  inferior  plexuses, 
adapt  the  behaviour  to  a  variety  of  external  requirements, 
have  been  but  recently  evolved;  so  that,  besides  being  ex- 
tensive and  intricate,  they  are  formed  of  much  less  perme- 
able channels.  Hence  when  the  nervous  system  is  not  fully 
charged,  these  latest  and  highest  structures  are  the  first  to 
fail.  Instead  of  being  instant  to  act,  their  actions,  if  ap- 
preciable at  all,  come  too  late  to  check  the  actions  of  the 
subordinate  structures.* 

♦  A  verification  seems  worth  naming.  The  sleeplessness  often  accom- 
panying nervous  debility,  sometimes  leads  to  the  occasional  use  of  morphia. 
A  dose  of  this  in  excess  of  the  need,  causing  undue  nervous  stimulation 
and  waste,  with  excitement  of  the  heart's  action,  entails  a  subsequent 


606  PHYSICAL  SYNTHESIS. 

§  263.  Among  deviations  towards  a  morbid  state  of  an 
opposite  kind,  let  us  first  note  such  as  are  apt  to  follow  tem- 
porary and  local  excitations.  These  arise  by  insensible  steps 
out  of  the  ordinary  deviations  which  accompany  functional 
activity. 

Each  part  of  the  brain,  like  the  brain  as  a  whole  and 
like  every  other  organ,  requires,  during  the  performance  of 
its  function,  an  augmented  supply  of  blood.  And  of  a 
cerebral  plexus  it  doubtless  holds  as  of  a  gland,  that  when 
called  into  action,  the  stimulus  sent  to  the  vaso-motor 
centre  is  reflected  to  the  vessels  of  the  part,  in  such 
way  as  to  cause  dilatation  of  them.  During  health, 
and  when  the  plexus  has  not  been  too  persistently 
exercised,  this  increased  flow  of  blood  through  it  ceases 
soon  after  the  demand  ceases.  But  extreme  continuance 
of  the  activity  even  in  those  who  have  well-toned 
vascular  systems,  and  very  moderate  continuance  of  it  in 
those  whose  vascular  systems  are  relaxed,  leads  to  local 
congestion  lasting  for  a  considerable  time;  and  there  then 
occurs  a  more  or  less  abnormal  genesis  of  the  correlative 
states  of  consciousness.  Strong  persons  frequently  illus^ 
trate  this  truth  on  landing  after  a  sea-voyage  of  a  day  or 
two:  they  continue  for  hours  to  have  illusive  perceptions 
of  rolling  and  pitching.  And  where,  as  in  nervous  people, 
the  cerebral  blood  vessels  easily  lose  their  contractility,  it 
commonly  happens  that  a  subject  discussed,  or  even  thought 
about  with  much  intensity,  monopolizes  consciousness  for  a 
long  time  afterwards  in  spite  of  efforts  to  exclude  it — 
often  thus  preventing  sleep.  Such  congestions  of  cerebral 
plexuses  have  various  degrees  of  duration — occasionally 

further  decrease  in  the  genesis  of  nervous  fluid  ;  and  the  irritability  and 
explosiveness  then  become  greater  than  usual.  There  seems  reason  to 
think,  too,  that  habitual  opium-eaters,  in  whom  this  worst  state  has  been 
made  chronic,  have  these  highest  plexuses  almost  paralyzed ;  and  are 
thus  bereft  of  the  feelings  which  should  adjust  their  conduct  in  its  re- 
moter and  more  complex  bearings.  The  lives  of  Coleridge  and  De 
Quincey  furnish  illustrations. 


EVIDENCE  PROM  ABNORMAL  VARIATIONS.         607 

causing  perversions  in  the  currents  of  ideas  persistent 
enough  to  attract  the  notice  of  those  around.  We 

find  here  a  further  verification  of  the  hypothesis.  Blood 
being  needful  for  the  performance  of  function,  and  the 
activity  of  function  being,  other  things  equal,  proportionate 
to  the  supply  of  blood,  it  naturally  happens  that  a  continue 
ance  of  the  supply  after  the  demand  for  function  has  ceased, 
causes  undue  readiness  to  resume  function.  When,  among 
the  data  of  psychology,  we  dealt  with  relations  between 
blood  and  nervous  action  and  feeling,  we  saw  that  an  excess 
of  blood  at  the  periphery  of  the  nervous  system,  as  in  an 
inflamed  part  of  the  skin,  is  accompanied  by  extreme  sensi- 
tiveness: the  molecular  change  then  set  up  in  the  dis- 
turbed end  of  a  nerve,  is  so  great  as  to  send  an  unduly  pow- 
erful discharge  to  the  point  where  feeling  is  aroused.  If 
we  transfer  these  conditions  from  periphery  to  centre,  we 
at  once  see  how  this  abnormal  genesis  of  ideas  results.  As 
nervous  discharges  of  all  kinds  are  diffused  and  re-diffused 
until  they  affect  the  whole  nervous  system,  we  must  re- 
gard every  sensation,  every  thought,  every  emotion,  as  a 
propagator  of  disturbances,  strong  or  weak,  throughout  the 
cerebral  masses.  The  reverberations  reaching  plexuses  in 
their  ordinary  states,  draw  from  them  but  feeble  reactions, 
and  accompanying  faint  additions  to  the  general  body  of 
consciousness.  But  when  the  reverberations  reach  plexuses 
made  unduly  sensitive  by  the  presence  of  much  blood,  the 
reactions  of  their  elements  are  unduly  strong — the  gushes 
of  nervous  fluid  liberated,  escaping  along  the  habitual  lines 
of  discharge,  arouse  the  correlative  states  of  consciousness 
not  faintly  but  vividly;  and  these,  standing  out  from  the 
background  of  consciousness,  become  the  predominant 
thoughts  and  feelings. 

If  these  physical  processes  are  extended  to  the  whole 

brain,  there  result  multitudinous  vivid  ideas  not  of  one  kind 

but   of   many   kinds.      All   the    cerebral   plexuses    being 

rendered  by  excess  of  blood  unduly  sensitive,  as  well  as 

40 


e08  PHYSICAL  SYNTHESIS. 

initiators  of  unduly  strong  disturbances,  consciousness  be- 
comes a  torrent  of  intense  thoughts  and  feelings;  and  if 
instead  of  congestion  we  have  inflammation,  order  and  pro- 
portion among  the  thoughts  and  feelings  are  quite  lost — 
there  is  delirium. 

§  264.  From  temporary  insanity,  partial  or  general,  of 
the  kind  caused  by  partial  or  general  derangements  of  cir- 
culation, congestive  or  inflammatory,  through  the  cerebral 
plexuses,  we  pass  to  the  kind  of  permanent  insanity  that 
ensues  when  such  derangements  of  circulation  become  per- 
manent. 

If  nutrition  of  a  cerebral  plexus  is  much  raised,  or  much 
altered  in  kind,  by  great  excess  of  blood,  the  thoughts  and 
feelings  initiated  are  likely  to  be  intensified  to  a  degree 
that  constitutes  them  illusions — we  get  monomania.  Carry- 
ing out  the  analogy  above  indicated,  we  may  say  that  as  a 
touch  on  an  inflamed  surface  of  skin  arouses  as  much  feel- 
ing as  a  cut  would  ordinarily  do;  so  a  hypersemic  nervous 
plexus  excited  by  some  slight  disturbance,  reacts  as 
violently  as  it  would  ordinarily  do  only  after  a  very 
strong  disturbance:  the  correlative  psychical  effect  being 
the  production  of  ideas  that  are  unduly  vivid — so  vivid 
sometimes  as  to  be  scarcely,  if  at  all,  distinguishable  from 
perceptions.  Supposing  this  state  lasts,  structural  changes 
occur  in  all  the  tissues  implicated.  Greatly  exalting  for  a 
time  the  rate  of  molecular  change,  producing  thickening  and 
deposits,  and  leaving  a  degradation  of  structure  inconsistent 
with  the  due  discharge  of  function,  the  hypersemia  may, 
after  making  the  correlative  psychical  states  unduly  vivid, 
end  in  enfeebling  them — so  entailing  a  changed  form  of 
mental  affection. 

If  a  chronic  vascular  derangement,  or  derangement  of 
nutrition  otherwise  caused,  extends  to  many  or  all  of  the 
cerebral  plexuses,  general  insanity  would  seem  fairly  in- 
ferable.   Should  it  be  said  that  a  deviation  from  the  normal 


EVIDENCE  FROM  ABNORMAL  VARIATIONS.         609 

rate  of  tissue-metamorphosis  throughout  the  cerebrum  at 
large,  either  by  increase  or  decrease,  would  seem  only  to 
necessitate  a  corresponding  exaltation  or  depression  of  all 
the  mental  powers,  and  not  a  derangement  of  them,  I  reply 
as  before  (§260)  that  derangement  of  them  is  implied  by 
any  disturbance  of  the  proportions  among  the  intensities  of 
states  of  consciousness,  and  that  such  disturbance  is  caused 
by  anything  that  modifies  them  all  indiscriminately.  If  the 
strengths  of  the  nervous  discharges  are  so  raised  that  those 
passing  along  the  less  permeable  channels  set  up  molecular 
changes,  and  arouse  correlative  feelings,  almost  or  quite  as 
strong  as  the  sensations  aroused  by  peripheral  stimuli,  the 
gradations  that  normally  exist  among  states  of  consciousness 
in  respect  of  their  degrees  of  vividness  and  degrees  of  co- 
hesion, are  either  destroyed  or  seriously  altered — judgment 
being  perverted  to  a  proportionate  extent.  And  a  perver- 
sion of  judgment  will  likewise  result  if,  from  an  opposite 
physical  cause,  some  of  the  states  of  consciousness  become 
too  faint  or  disappear. 

It  is  needful  to  add  that  though  thus  far  chronic  vascular 
derangements,  and  derangements  of  local  nutrition  entailed 
by  them,  have  been  named  as  causes  of  insanity,  the  impli- 
cation that  they  are  the  only  causes  is  by  no  means  intended. 
Effete  matters  may,  if  they  accumulate  in  the  blood,  produce 
molecular  disturbances  in  the  nervous  centres  through  which 
they  are  continually  carried;  and  molecular  disturbances 
so  set  up  will  have  for  their  concomitants  disorders  of  the 
mental  states.  Or  instead  of  a  normal  product  of  decompo- 
sition that  has  not  been  duly  excreted,  some  introduced 
virus,  or  some  morbid  matter  arising  from  constitutional 
disease,  may,  by  thus  acting  as  an  irritant,  perturb  the  cur- 
rents of  thoughts  and  feelings.  That  an  impure  blood  is 
thus  a  possible,  and  indeed  a  probable,  cause  of  insanity,  we 
find  good  reason  for  believing. 

§  265.  For  we  bring  on  a  species  of  temporary  insanity 


610  PHYSICAL  SYNTHESIS. 

by  putting  certain  poisons  into  the  blood.  Substances  which, 
like  opium  and  hashish,  exalt  the  rate  of  molecular  change 
in  the  nervous  centres,  so  intensify  the  feelings  and  ideas 
as  to  cause  illusions. 

I  need  not  follow  out  in  detail  the  parallelism  between  the 
effects  of  increased  pressure  of  nervous  fluid  produced  by 
these  drugs  and  increased  pressure  otherwise  produced. 
Here,  as  before,  there  is  such  exaltation  of  ideal  feelings  as 
brings  them  near  to  real  feelings  in  distinctness;  such 
strengthening  of  the  relations  among  them  as  causes  failing 
memories  to  arise  with  clearness;  such  facility  in  the  forma- 
tion of  remote  and  complex  connexions  of  thoughts  as  con- 
stitutes a  transfigured  imagination;  and  such  widening  of 
consciousness  as  changes  its  quiet  flow  into  a  flood. 

One  thing  only  will  I  draw  attention  to — the  verification 
yielded  of  a  foregoing  hypothesis  respecting  the  genesis  of 
"  states  of  mind."  As  a  corollary  from  the  laws  of  associa- 
tion translated  into  terms  of  nervous  action,  we  concluded 
that  when  the  pressure  of  nervous  fluid  is  low,  the  diffused 
discharges  will  be  so  distributed  that  the  faintly  revived 
feelings  of  pain  will  preponderate;  that  when  the  nervous 
pressure  is  up  to  par,  the  aggregate  of  feelings  indistinctly 
awakened,  pleasurable  and  painful,  will  form  a  neutral  com- 
pound; and  that  when  the  pressure  is  high,  the  pleasurable 
elements  of  consciousness,  relatively  as  well  as  positively 
increased  in  their  amount,  will  constitute  a  sense  of  happi- 
ness. Here  it  is  to  be  observed  that  artificial  happiness  is 
produced  by  artificial  increase  of  pressure.  The  delightful 
reveries  of  the  opium-eater  constitute  the  temptation  which 
he  finds  it  so  difficult  to  resist.  And  similarly  with  Indian 
hemp:  "  It  is  real  happiness  which  is  produced  by  hashish," 
says  M.  Moreau. 

§  266.  To  complete  the  outline  of  the  evidence  furnished 
by  abnormal  variations,  a  few  words  must  be  added  on  the 
effects  of  anaesthetics.  These  change  the  nervous  actions  and. 


EVIDENCE  PROM  ABNORMAL  VARIATIONS.         611 

correspondingly,  change  the  states  of  mind.  Are  the  changes 
they  work  interpretable  as  agreeing  with  the  foregoing  gen- 
eral doctrine?    In  great  measure,  I  think,  if  not  wholly. 

It  is  admitted  as  holding  generally  of  these  various  agents 
— alcohol,  ether,  chloroform,  nitrous  oxide,  &c. — that  when 
their  anaesthetic  effects  begin,  the  highest  nervous  actions 
are  the  first  to  be  arrested;  and  that  the  artificial  paralysis 
implicates  in  descending  order  the  lower,  or  simpler,  or 
better-established  nervous  actions.  Incipient  intoxication 
shows  itself  in  a  failure  to  form  involved  and  abstract  rela- 
tion of  ideas,  while  it  remains  possible  to  form  simpler  rela- 
tions. In  the  anaesthesia  produced  for  surgical  purposes, 
we  have  less  opportunity  of  observing  that  the  like  happens; 
but  assuming  that  it  does  so,  we  find  all  the  successive  symp- 
toms conformable  in  their  order  to  the  hypothesis.  Ac- 
cording to  M.  Flourens  and  Dr.  Snow,  as  quoted  and,  on 
the  whole,  endorsed  by  Dr.  Anstie,  the  aether-narcosis  pro- 
duces the  loss  of — "  1.  The  local  sensibility  of  extreme 
parts,  and  the  control  of  certain  muscles  situated  in  those 
parts.  2.  The  intellectual  powers.  3.  The  power  of  co- 
ordination of  the  locomotive  organs  generally.  4.  The 
power  of  perceiving  sensory  impressions,  even  from  parts 
little  removed  from  the  spinal  centres.  5.  The  power  of 
breathing.  6.  The  movements  of  vegetative  life — e.g.^  of 
the  heart,  intestines,  &c."  Here  loss  of  the  intellectual 
powers  is  placed  after  loss  of  sensibility  "  of  extreme  parts  " ; 
but  this  discrepancy  is  due  to  the  fact  that  paralysis  of  the 
higher  intellectual  powers,  necessarily  inconspicuous  under 
the  circumstances,  is  not  specifically  named,  even  where 
observable;  and  that  only  when  the  perceptions  become 
confused  are  the  intellectual  powers  set  down  as  lost.  The 
experiments,  both  with  ether  and  chloroform,  show  clearly 
that  some  incoherence  of  thought  is  the  first  noticeable  effect. 

Making  this  correction  of  the  statement,  we  may  say  that 
anaesthetics  stop  first  the  discharges  along  the  incipient  lines 
of  nervous  communication ;  next  the  discharges  along  lines 


^ 


612  PHYSICAL  SYNTHESIS. 

a  little  better  formed ;  and  so  on,  until  finally  they  stop  the 
discharges  along  the  fully-established  lines.  Limiting  our- 
selves for  brevity  to  the  two  extremes,  we  see  that  on  the 
one  hand,  incoherence  among  the  more  involved  thoughts 
implies  that  those  least  permeable  channels  of  nervous  dis- 
charge that  have  been  formed  by  the  comparatively-few 
experiences  of  the  individual,  have  become  impermeable; 
while,  on  the  other  h^nd,  when  the  functions  of  the  visceral 
nervous  system  cease,  the  implication  is  that  discharges  no 
longer  pass  even  through  those  most  permeable  channels 
which  have  been  inherited,  in  a  ready-organized  form,  from 
an  ancestry  that  runs  back  not  simply  through  numberless 
individuals,  but  through  numberless  species. 

Though  the  effects  of  anaesthetics  thus  yield  confirmation 
of  the  belief  that  lines  of  nervous  communication  become 
permeable  in  proportion  as  the  discharges  through  them  are 
strong  and  frequent,  they  present  some  apparent  obstacles 
to  it.  How  is  the  preliminary  stage  of  excitement,  and  even 
mental  exaltation,  reconcilable  with  the  argument?  How 
are  the  differential  effects  of  different  anaesthetics  to  be  ex- 
plained ?  How  does  it  happen  that  in  some  cases  sensation  is 
abolished  while  there  continues  some  consciousness  of  things 
around?  I  believe  there  are  answers  to  these  questions; 
but  this  general  exposition  would  be  too  much  encumbered 
by  including  them  in  it.* 

§  267.  I  have  reserved  till  the  last  what  needs  to  be  said 
in  answer  to  objections  which  critical  readers  have  probably 
made,  now  to  one  and  now  to  another,  of  the  several  fore- 
going interpretations.  This  I  have  done  with  the  inten- 
tion of  ultimately  pointing  out  that  the  interpretations  must 
be  taken  not  separately  but  together.  The  many  causes 
of  variation  at  work,  interfere  with  one  another  in  multi- 
tudinous ways  and  degrees — each  is  influenced  by  all  and  all 
by  each. 

•  See  Appendix. 


EVIDENCE  FROM  ABNORMAL  VARIATIONS.         613 

Due  co-ordination  of  any  set  of  nervous  discharges,  and 
production  of  the  appropriate  combination  of  mental  states 
accompanying  it,  depends,  primarily,  on  the  existence  of 
fitly-organized  nervous  plexuses  in  fitly-adjusted  molecular 
states;  and  this  pre-supposes  that  the  approximately-adapted 
structures  which  the  individual  inherited,  have  had  their 
adaptation  completed  by  his  own  activities.  It  depends, 
secondarily,  on  the  general  supply  of  nervous  fluid ;  and  the 
physical  processes  and  accompanying  psychical  states  will 
vary  according  as  the  pressure  of  nervous  fluid  is  high,  or 
moderate,  or  low.  And  it  depends,  tertiarily,  on  the  extent 
to  which  nervous  fluid  is  being  at  the  time  drawn  off  by 
other  discharges — to  the  viscera,  to  the  muscles,  or  to  other 
parts  of  the  nervous  system.  Along  with  these  general  de- 
termining causes  have  to  be  taken  into  account  many  more 
special  determining  causes — the  state  of  the  blood  as  rich  or 
poor,  as  well  or  ill  aerated,  as  freed  or  not  freed  from  this  or 
that  waste  matter;  the  state  of  the  blood  as  containing 
morbid  products  or  foreign  substances;  the  supply  of  blood 
to  the  plexuses  concerned,  which  depends  partly  on  habit, 
as  involving  frequent  or  infrequent  action  of  them,  and 
partly  on  the  character  of  the  blood  vessels,  as  contractile 
or  the  reverse ;  and,  lastly,  the  state  of  these  plexuses  as  modi- 
fied by  chronic  derangements  of  nutrition  due  to  local  in- 
flammation and  its  sequelai. 

Remembering  that  all  these  co-operative  causes  have  to 
be  taken  into  account,  we  shall,  I  think,  see  little  difficulty 
in  reconciling  the  various  anomalies  with  the  general  prin- 
ciple set  forth. 


CHAPTER  X. 


EESULT8. 


§  268.  A  not  unsatisfactory  fulfilment  of  the  anticipation 
with  which  we  set  out  has,  I  think,  been  reached.  In  the 
General  Synthesis  mental  development,  traced  up  from  its 
beginnings,  was  represented  as  a  correspondence  between 
inner  and  outer  actions,  that  extends  in  Space  and  in  Time, 
while  it  increases  in  Speciality,  in  Generality,  and  in  Com- 
plexity. The  Special  Synthesis  carried  further  this  interpre- 
tation of  mental  development,  by  showing  how  the  advanc- 
ing correspondence,  when  translated  into  the  more  familiar 
terms  of  Reflex  Action,  Instinct,  Memory,  Reason,  Feeling, 
and  Will,  is  comprehensible  as  a  continuous  process  natu- 
rally caused.  And  in  the  Physical  Synthesis  just  concluded, 
this  continuous  process  naturally  caused  has  been  inter- 
preted as  a  cumulative  result  of  physical  actions  that  con- 
form to  known  physical  principles. 

iNTerve  being  supposed  to  have  the  molecular  structure 

and  properties  which,  at  the  beginning  of  this  work,  we 

found  such  numerous  reasons  for  assigning  to  it;  we  have 

inferred  from  established  laws  of  motion,  that  the  molecular 

change  wrought  in  it  by  every  discharge  it  conveys,  leaves 

it  in  a  state  for  conveying  a  subsequent  like  discharge  with 

less  resistance.     This,  being  the  universal  law  of  nervous 

action,  explains  the  universal  law  of  intelligence.     In  the 

foregoing  chapters  we  have  compared  the  various  corollaries 

614 


RESULTS.  615 

of  the  one  with  the  various  implications  of  the  other;  and 
we  have  found  that,  from  the  simplest  to  the  most  complex 
cases,  physical  principle  and  psychical  manifestation  agree. 
Regarding  as  superposed,  each  on  the  preceding,  the  struc- 
tural effects  produced  generation  after  generation  and  spe- 
cies after  species,  we  have  formed  a  general  conception  of 
the  manner  in  which  the  most  complex  nervous  systems 
have  arisen  out  of  the  simplest.  Simultaneously,  we  have 
been  helped  to  understand  more  clearly  the  natures  of  the 
various  modes  of  consciousness — perceptions,  ideas,  emo- 
tions, &c;  And,  by  pursuing  the  reasoning  to  its  remoter 
consequences,  we  have  found  that  both  normal  and  abnormal 
variations  of  mental  processes,  even  up  to  the  changes  of 
mood  accompanying  bodily  changes  and  the  ecstatic  feelings 
aroused  by  certain  drugs,  are  rendered  comprehensible. 

The  sufficiency  of  this  general  principle  to  account  for  the 
facts,  can  of  course  be  alleged  only  on  the  assumption  that 
changes  wrought  in  nervous  structures  by  nervous  functions 
are  inheritable.  Tacitly  throughout  the  divisions  preceding 
it,  and  avowedly  throughout  this  Physical  Synthesis,  it  has 
been  taken  for  granted  that  from  generation  to  generation 
there  descend  alterations  of  structure;  both  of  the  kind 
called  spontaneous,  and  of  the  kind  arising  from  functional 
actions.  Throughout  the  earlier  stages  of  nervous  evolu- 
tion, a  leading  and  perhaps  most  active  cause,  has  been  the 
survival  of  individuals  in  which  indirect  influences  have 
produced  favourable  variations  of  nervous  structure.  But 
throughout  its  later  stages,  the  most  active  cause  has  been 
the  direct  production  by  functional  changes  of  correspond- 
ing changes  of  nervous  structure,  and  the  transmission  of 
these  to  posterity.  Considering  how  involved  are  the  nerv- 
ous systems  of  superior  creatures,  there  apply  here  with  espe- 
cial force  the  reasons  before  given  {Prind/ples  of  Biology 
§  166)  for  concluding  that  natural  selection  is  an  inadequate 
cause  of  evolution  where  many  co-operative  parts  have  to 
be  simultaneously  modified;  and  that  in  such  cases  the  in- 


QIQ  PHYSICAL  SYNTHESIS. 

heritance  of  functionally-produced  modifications  becomes 
the  leading  agency — survival  of  the  fittest  serving  as  an  aid. 
But  these  processes  of  direct  and  indirect  equilibration 
being  postulated  as  acting  on  all  organisms  throughout  all 
time,  we  see  that  joining  with  them  the  inferred  effect  of 
every  nervous  discharge  upon  every  channel  passed  through, 
we  get  an  adequate  explanation  of  nervous  evolution,  and 
the  concomitant  evolution  of  Mind. 

§  269.  "  Thus,  then,  we  are  brought  face  to  face  with 
unmistakable  materialism,"  will  exclaim  many  a  reader. 
"  Thus,  then,  it  is  positively  asserted  that  Mind  is  a  growth, 
and  that  it  grows  after  the  same  general  method  as  does 
the  meanest  fungus  or  the  most  degraded  worm.  Thus, 
then,  we  must  infer  that  the  profoundest  intuitions  of  the 
discoverer  and  the  sublimest  inspirations  of  the  poet — the 
most  abstract  conceptions  of  the  mathematician  as  well  as 
the  noblest  emotions  of  self-sacrificing  sympathy — are  but 
properties  of  certain  matters  arranged  in  particular  ways." 

Notwithstanding  the  explanations  that  have  been  from 
time  to  time  given,  such  will,  I  doubt  not,  be  a  frequent 
apostrophe.  So  favourite  a  mode  of  meeting  the  inferences 
drawn,  is  sure  to  be  again  employed;  though,  as  shown  al- 
ready, it  tells  duly  against  a  doctrine  that  has  been  repudi- 
ated. The  general  relation  between  mental  manifestations 
and  material  structures  traced  out  in  the  foregoing  chapters, 
has  implications  identical  with,  and  no  wider  than,  those 
which  familiar  experiences  thrust  upon  us.  That  drowsiness 
impedes  thinking,  that  wine  excites  or  stupefies  according 
to  amount  and  circumstances,  that  great  loss  of  blood  pro- 
duces temporary  unconsciousness,  and  that  the  unconscious- 
ness of  death  results  if  breathing  be  stopped  for  a  few  min- 
utes; are  facts  admitted  by  every  one,  be  his  theory  of 
things  what  it  may.  That  you  cannot  get  out  of  the  un- 
developed child,  thoughts  and  feelings  like  those  you  get 
out  of  the  developed  man;  that  the  idiot,  with  brain  per- 


RESULTS.  617 

manently  arrested  in  its  growth,  remains  permanently  in- 
capable of  any  but  the  simplest  mental  actions;  are  proposi- 
tions not  denied  by  the  most  intemperate  reviler  of  physio- 
logical psychology.  But  one  who  recognizes  such  facts  and 
propositions,  is  just  as  much  chargeable  with  materialism 
as  one  who  puts  together  facts  and  propositions  like  those 
which  constitute  the  foregoing  exposition.  Whoever  grants 
that  from  the  rudimentary  consciousness  implied  by  the 
vacant  stare  of  the  infant,  up  to  the  quickly-apprehensive, 
far-seeing,  and  variously-feeling  consciousness  of  the  adult, 
the  transition  is  through  slow  steps  of  mental  progress  that 
accompany  slow  steps  of  bodily  progress,  tacitly  asserts  the 
same  relation  of  Mind  and  Matter  which  is  asserted  by  one 
who  traces  out  the  evolution  of  the  nervous  system  and  the 
accompanying  evolution  of  intelligence,  from  the  lowest  to 
the  highest  forms  of  life. 

But,  as  said  here  and  before,  the  supposed  implication  is 
not  the  true  implication.  Let  me  once  more  point  out  what 
the  true  implication  is.  By  way  of  preparation,  however, 
we  will  first  observe  how  the  above  apostrophe  might  be 
met  by  those  to  whom  it  would  be  fitly  addressed. 

§  270.  "  Your  reproaches  seem  to  me  strangely  inconsis- 
tent with  your  avowed  beliefs  and  sentiments,"  might  say 
the  materialist  to  his  opponent.  "  You  profess  the  pro- 
foundest  reverence  for  the  Creative  Power,  from  which 
you  hold  the  Universe  to  have  proceeded.  Yet  of  the  visi- 
ble and  tangible  part  of  the  Universe,  you  speak  in  a  way 
that  would  be  appropriate  were  its  origin  diabolical;  and 
you  taunt  me  because  I  recognize  in  that  which  you  treat 
with  so  much  scorn,  powers  no  less  marvellous  than  those 
manifested  in  the  human  mind. 

"  You  see  this  piece  of  steel — cold,  motionless,  and,  as 
you  suppose,  insensitive  to  all  that  goes  on  around.  An 
artizan  uses  a  portion  of  it  for  making  the  balance-wheel  of 


618  PHYSICAL  SYNTHESIS. 

a  watch.  Inunediately  it  proves  itself  modifiable  by  changes 
of  temperature  which  our  dull  senses  fail  to  appreciate. 
Though  by  no  direct  measures  can  we  detect  an  alteration 
in  the  length  of  its  beat;  yet,  indirectly,  by  finding  that  it 
loses  one  beat  in  a  hundred  thousand,  we  get  proof  that  an 
imperceptible  increase  in  the  molecular  agitation  propagated 
to  it  by  surrounding  things,  has  augmented  its  diameter  and 
expanded  all  its  parts  in  the  same  ratio.  Take  anotlier  bit 
of  this  same  apparently  inert  substance;  shape  it  appropri- 
ately; bring  it  under  the  influence  of  an  adjacent  magnet; 
and  throughout  its  mass  there  is  wrought,  in  some  incom- 
prehensible way,  an  invisible  change  which  enables  it  to  do 
— what?  *  To  point  north  and  south,'  you  say.  Yes;  but 
to  do  far  more  than  this.  Its  perturbations  will  now  show 
to  an  instructed  eye,  the  rise  and  progress  of  a  cyclone  in 
the  Sun. 

"  And  what  is  the  constitution  of  this  seemingly-simple 
matter,  which  thus  tells  of  things  near  and  remote  that  re- 
main otherwise  unknown  ?  In  the  minutest  visible  fragment 
of  it  there  are  millions  of  units  severally  oscillating  with  un- 
imaginable speed;  and  physicists  show  us  that  the  ampli- 
tudes of  their  oscillations  vary  from  moment  to  moment, 
according  as  the  temperatures  of  surrounding  objects  vary. 
Nay,  much  more  than  this  is  now  inferable.  Each  unit  is 
not  simple  but  compound — not  a  single  thing  but  a  system 
of  things.  Spectrum-analysis  has  made  it  manifest  that 
every  molecule  of  this  so-called  elementary  substance  is  a 
cluster  of  minor  molecules  differing  in  their  weights  and 
rhythms.  Such  being  the  complexity  of  matters  we  lately 
thought  simple,  judge  what  is  the  complexity  of  matters 
we  know  as  compounds.  In  each  molecule  of  an  oxide  or 
an  acid,  the  chemist  sees  one  of  these  systems  united  with 
one,  two,  three,  or  more  systems  of  another  kind  that  are 
similarly  involved.  Ascending  to  orders  of  compounds  suc- 
cessively more  heterogeneous,  he  finds  himself  obliged  to 
recognize     molecular     complexities     unrepresentable     in 


RESULTS.  619 

thought;  until,  on  reaching  organic  matter,  he  comes  to 
molecules  each  of  which  (taking  into  account  the  compo- 
site nature  of  its  so-called  elements)  contains  literally  more 
atoms  than  the  visible  heavens  contains  stars — atoms  com- 
bined, system  within  system,  in  such  ways  that  each  atom, 
each  system,  each  compound  system,  each  doubly-compound 
system,  has  its  motion  in  relation  to  the  rest,  and  is  capa- 
ble of  perturbing  the  rest  and  of  being  perturbed  by  them. 

"  This  activity  and  this  sensitiveness,  which  the  investi- 
gator marvels  at  the  more  the  deeper  his  discoveries  reach, 
is  possessed  in  common  by  ponderable  matter  and  by  the 
seemingly-imponderable  matter  pervading  space.  That  the 
ether,  so  extreme  in  tenuity  that  we  can  scarcely  represent 
it  to  ourselves  as  having  materiality,  is  nevertheless  com- 
posed of  units  which  move  in  conformity  to  mechanical 
laws,  is  now  a  common-place  of  science.  Hypothetically 
endowing  these  units  with  momenta,  and  assuming  that  in 
each  undulation  their  courses  are  determined  by  composi- 
tion of  forces,  mathematicians  long  ago  found  themselves 
able  not  only  to  interpret  known  properties  of  the  light  con- 
stituted by  ethereal  undulations,  but  to  assert  that  it  had 
unobserved  properties;  which  were  thereupon  proved  by 
observation  to  exist.  Far  greater  community  than  this  has 
been  disclosed  between  the  ponderable  and  the  imponder- 
able: the  activities  of  either  are  unceasingly  modified  by 
the  activities  of  the  other.  Each  complex  molecule  of  mat- 
ter oscillating  as  a  whole — nay,  each  separate  member  of  it 
independently  oscillating,  causes  responsive  movements  in 
adjacent  ethereal  molecules,  and  these  in  remoter  ones  with- 
out limit;  while,  conversely,  each  ethereal  wave  reaching 
a  composite  molecule,  changes  more  or  less  its  rhythmical 
motions,  as  well  as  the  rhythmical  motions  of  its  component 
clusters  and  those  of  their  separate  members. 

"  Nor  do  the  revelations  end  here.  The  discovery  that 
matter,  seemingly  so  simple,  is  in  its  ultimate  structure  so 
amazingly  involved;  the  discovery  that,  while  it  appears  to 


620  PHYSICAL  SYNTHESIS. 

be  inert,  it  is  the  seat  of  activities  immense  in  quantity  and 
complication;  and  the  discovery  that  its  molecules,  pulsat- 
ing with  almost  infinite  rapidity,  propagate  their  pulses  into 
the  all-surrounding  ether  which  carries  them  through  in- 
conceivable distances  in  infinitesimal  times;  serve  to  intro- 
duce us  to  the  yet  more  marvellous  discovery  that  molecules 
of  each  kind  are  specially  affected  by  molecules  of  the  same 
kind  existing  in  the  farthest  regions  of  space.  Units  of 
sodium  on  which  sunlight  falls,  beat  in  unison  with  their 
kindred  units  more  than  ninety  millions  of  miles  off,  by 
which  the  yellow  rays  of  the  Sun  are  produced.  Nay,  even 
this  is  a  totally  inadequate  illustration  of  the  sympathy  dis- 
played by  the  matter  composing  the  visible  Universe.  The 
elements  of  our  Earth  are  thus  connected  by  bonds  of  inter- 
dependent activity,  with  the  elements  of  stars  so  remote 
that  the  diameter  of  the  Earth's  orbit  scarcely  serves  as  a 
unit  of  measure  to  express  their  distances. 

"  This,  then,  is  the  form  of  being  you  speak  of  so  con- 
temptuously. And,  because  I  ascribe  to  this  form  of  being 
powers  which,  though  not  more  wonderful  than  these,  are 
more  involved,  you  scowl  at  me.  If,  instead  of  saying  that 
I  degrade  Mind  to  a  level  with  Matter,  you  were  to  say  that 
I  elevate  Matter  to  a  level  with  Mind,  you  would  express  the 
fact  more  nearly." 

§  271.  Such  we  may  imagine  to  be  the  reply  of  a  mate- 
rialist of  the  cruder  sort,  who  failed  to  present  his  belief 
under  its  right  aspect.  Let  us  now  listen  to  one  of  the  same 
general  school,  whom  we  may  suppose  to  understand  better 
the  meanings  of  these  truths  which  science  has  revealed. 

"  The  name  you  give  me  is  intended  to  imply  that  I 
identify  Mind  with  Matter.  I  do  no  such  thing.  I  identify 
Mind  with  Motion ;  and  Motion  is  inconceivable  by  us  as  in 
any  sense  material.  Observe  this  weight.  Now  it  is  mo- 
tionless; now  I  relax  my  grasp  and  it  begins  to  move  to- 
wards the  Earth.      What  has  suddenly  entered  into  it? 


RESULTS.  621 

Though  apparently  unchanged  in  all  its  properties,  this,  or 
any  other  mass,  needs  but  to  have  a  quantity  of  motion 
impressed  on  it  by  impact  or  otherwise,  and  it  thereafter 
goes  on  changing  its  place  in  space  at  the  same  velocity;  so 
long  as  it  meets  with  no  other  matter  and  has  no  other 
motion  impressed  on  it.  What  is  this  source  of  activity? 
How  does  it  dwell  in  the  weight?  and  in  what  manner 
does  it  cause  the  weight  to  take  every  instant  a  new  place? 
On  the  one  hand,  we  cannot  assert  that  Motion  exists  as  a 
something  separate  from  Matter;  since  asserting  this  implies 
that  we  can  think  of  it  as  having  independent  attributes.  On 
the  other  hand,  we  cannot  assert  that  Motion  has  no  separate 
existence;  since,  if  it  has  not,  how  can  we  think  of  it  as 
transferred  from  one  body  to  another?  Moreover,  the  ap- 
pearance and  disappearance  of  Motion  raise  the  questions — 
Where  was  it  previously?  and  where  is  it  now?  When  this 
weight  falls,  we  have  not  only  to  ask — Whence  has  its  mo- 
tion come?  but  when  it  strikes  the  pavement  we  have  to  ask  A 
— To  what  place  has  its  motion  gone?  Part  of  it  was  passed  ?  1 
on  to  the  particles  deranged  by  the  blow;  part  of  it,  trans- 
formed into  sound-waves,  has  been  dispersed  through  the 
surrounding  air;  and,  even  while  I  speak,  part  of  it  has 
already  travelled  millions  of  miles  away  in  the  shape  of 
ethereal  undulations.  This  Motion,  then — now  diffused 
and  imperceptible,  now  suddenly  individualized  and  pro- 
ducing visible  changes,  now  re-diffused  in  various  forms 
and  part  of  it  instantly  transferred  to  immeasurable  dis- 
tances— is  of  a  nature  wholly  inscrutable;  and  if  I  identify 
Mind  with  it,  I  identj.fy  Mind  with  something  no  less  mys- 
terious than  itself." 

"  You  think  of  me  as  seeing  no  essential  difference  be- 
tween Mind  and  the  material  properties  of  brain.  As  well ' 
might  I  think  of  you  as  seeing  no  essential  difference  be- 
tween music  and  the  material  properties  of  the  piano  from 
which  it  is  evoked.  Because  you  assert  that  music  is  pro- 
duced from  the  piano,  do  you  therefore  assert  any  kinship 


622  PHYSICAL  SYNTHESIS. 

in  nature  between  a  piano-string  and  the  serial  pulses  it  gen- 
erates when  struck?  Or  do  you  therefore  assert  an  identity 
between  such  pulses  and  the  relations  among  them  which 
constitute  cadences  and  harmonies?  No  more  then  do  I, 
in  asserting  the  dependence  of  Mind  on  nervous  structure, 
assert  any  kinship  in  nature  between  the  matter  of  a  nerve- 
cell  and  the  actions  that  arise  from  it,  or  between  these 
actions  and  those  relations  among  them  which  constitute 
thought.  Do  you  object  to  the  parallel  because  the  piano 
remains  silent  till  touched,  while  the  brain  acts  without 
external  help?  I  reply  that  in  either  case  the  power  is  de- 
rived from  without,  and  that  the  effect  of  the  structure  is 
simply  that  of  transforming  it.  As  the  motion  given  to  an 
automatic  musical  instrument  passes  through  its  specialized 
structure  and  comes  out  in  the  form  of  particular  combina- 
tions of  serial  pulses,  simultaneous  and  successive;  so  the 
motion  locked  up  in  a  man's  food,  added  to  that  directly 
received  through  his  senses,  is  transformed  while  passing 
through  his  nervous  system  into  those  combinations  of  nerv- 
ous actions  which,  on  their  subjective  faces,  are  thoughts 
and  feelings. 

"  But  this  analogy  is  far  too  rude  to  convey  a  true  con- 
ception. Not  with  sensible  Motion,  even  though  it  be  that 
of  the  invisible  air,  has  Mind  any  direct  kinship;  but  only 
with  insensible  Motion,  of  kinds  inconceivably  more  subtle 
and  immeasurably  more  rapid.  Not  to  combined  undula- 
tions of  ponderable  substance,  however  rare,  is  Mind  to  be 
assimilated;  but  only  to  combined  undulations  of  the  all- 
pervading  imponderable  substance  which  we  know  of  only 
by  inference  from  their  effects.  The  activities  of  this  im- 
ponderable substance,  though  far  simpler,  and  in  that  re- 
spect far  lower,  than  the  activities  we  call  Mind,  are  at  the 
same  time  far  higher  than  those  we  call  Mind  in  respect  of 
their  intensity,  their  velocity,  their  subtlety.  What  has 
been  gained  in  adaptability  has  been  lost  in  vivacity. 
Though  Mind  brings  into  adjustment  the  apparatus  by 


RESULTS.  638 

which  certain  ethereal  undulations  emanating  from  the  Sun 
are  brought  to  a  focus,  yet  Mind  cannot,  like  these  concen- 
trated undulations,  dissipate  the  diamond  placed  in  that 
focus.  Though  Mind  is  capable  of  devising  an  electric  tele- 
graph, yet  it  remains  wholly  insensible  to  those  slight 
molecular  agitations  on  the  other  side  of  the  Earth  which 
transform  themselves  into  sensible  motions  on  this  side. 
And  now  that  the  rates  of  our  ideas  and  volitions  have  been 
measured,  we  learn  that  though  thought  is  quick,  light  is 
many  millions  of  times  quicker. 

"  Your  conceptions,  O  Spiritualist,  is  far  too  gross  for  me. 
I  know  not  what  may  be  the  extent  to  which  you  have  re- 
fined this  creed  which  you  inherit  from  aboriginal  men. 
Disembodied  spirit  was  conceived  by  your  remote  ancestors 
(as  it  is  still  conceived  by  various  existing  savages)  as  ma- 
terial enough  to  take  part  in  battle,  and  even  to  be  killed 
over  again.  Becoming  less  concrete  and  definite  as  know- 
ledge increased,  the  idea  of  a  ghost  continued,  till  quite 
modem  days,  to  be  that  of  a  being  which  could  cause  alarm- 
ing noises  and  utter  words.  Even  your  quite-recent  an- 
cestors, transparent  as  they  supposed  the  substance  of  a 
ghost  to  be,  nevertheless  supposed  it  visible.  Possibly  you 
have  still  further  purified  their  belief.  But  whether  you 
confess  it  or  not,  you  cannot  think  of  disembodied  spirit 
without  thinking  of  it  as  occupying  a  separate  place  in 
space — as  having  position,  and  limits,  and  such  materiality 
as  is  implied  by  limits.  This  idea,  not  commended  to  me 
by  its  genealogy,  quite  unsatisfactory  in  its  nature,  an<J 
wholly  unsupported  by  evidence,  I  cannot  accept.  Mind, 
I  identify  with  that  which  is  not  relatively  immaterial  but 
absolutely  immaterial.  It  has  not  even  the  inconceivably 
refined  materiality  of  the  ether  which  fills  what  you  call 
empty  space;  but  it  is  assimilable  to  the  activities  mani- 
fested by  this  ether,  as  well  as  by  all  sensible  forms  of 
being.  Everywhere  in  unceasing  influx  and  efilux,  it  is 
that  which  is  for  ever  dissolving  and  re-forming  sensible  ex- 
41 


624  PHYSICAL  SYNTHESIS. 

istences  of  all  orders — organic  and  inorganic.  Pervading 
alike  the  space  which  is  occupied  and  the  space  which  seems 
to  us  unoccupied,  it  gives  to  the  ponderahle  substance  filling 
the  one  its  powers  of  action  and  reaction,  and  to  the  im- 
ponderable substance  filling  the  other  its  powers  of  con- 
veying actions  and  reactions  from  one  body  to  another.  So 
that  when  there  happens  some  vast  catastrophe  like  that  of 
which  the  star  near  e  Coronw  was  lately  the  seat,  it  is  at  once 
the  agent  by  which  the  transformation  is  wrought  and  the 
agent  by  which  is  conveyed,  with  almost  infinite  speed 
through  the  Universe,  the  resulting  tremor  felt  on  the  sur- 
faces of  its  countless  worlds." 

§  272.  Comparatively  consistent  as  is  this  answer,  and 
serving  though  it  does  to  throw  back  with  added  force  the 
reproaches  of  the  spiritualist,  it  is  not  the  answer  to  be  here 
given.  In  the  closing  paragraphs  of  First  PrmcipleSy  and 
again  in  the  earlier  parts  of  the  present  work,  the  position 
taken  was,  that  the  truth  is  not  expressible  either  by  Mate- 
rialism or  by  Spiritualism,  however  modified  and  however 
refined.  Let  me  now,  for  the  last  time,  set  forth  the  ulti- 
mate implications  of  the  argument  running  through  this 
volume,  as  well  as  through  preceding  volumes. 

Carried  to  whatever  extent,  the  inquiries  of  the  psycho- 
logist do  not  reveal  the  ultimate  nature  of  Mind;  any  more 
than  do  the  inquiries  of  the  chemist  reveal  the  ultimate 
nature  of  Matter,  or  those  of  the  physicist  the  ultimate  na- 
ture of  Motion.  Though  the  chemist  is  gravitating  towards 
the  belief  that  there  is  a  primitive  atom,  out  of  which  by 
variously-arranged  unions  are  formed  the  so-called  ele- 
ments, as  out  of  these  by  variously-arranged  unions  are 
formed  oxides,  acids,  and  salts,  and  the  multitudinous  more 
complex  substances;  yet  he  knows  no  more  than  he  did  at 
first  about  this  hypothetical  primitive  atom.  And  simi- 
larly, though  we  have  seen  reason  for  thinking  that  there 
is  a  primitive  unit  of  consciousness,  that  sensations  of  all 


RESULTS.  626 

orders  are  formed  of  such  units  combined  in  various  rela- 
tions, that  by  the  compounding  of  these  sensations  and  their 
various  relations  are  produced  perceptions  and  ideas,  and  so 
on  up  to  the  highest  thoughts  and  emotions;  yet  this  unit 
of  consciousness  remains  inscrutable.  Suppose  it  to  have 
become  quite  clear  that  a  shock  in  consciousness  and  a  mo- 
lecular motion,  are  the  subjective  and  objective  faces  of  the 
same  thing;  we  continue  utterly  incapable  of  uniting  the 
two,  so  as  to  conceive  that  reality  of  which  they  are  the  op- 
posite faces.  Let  us  consider  how  either  face  is  framed  in 
our  thoughts. 

The  conception  of  a  rhythmically-moving  mass  of  sensible 
matter,  is  a  synthesis  of  certain  states  of  consciousness  that 
stand  related  in  a  certain  succession.  The  conception  of  a 
rhythmically-moving  molecule,  is  one  in  which  these  states 
and  their  relations  have  been  reduced  to  the  extremest  limits 
of  dimension  representable  to  the  mind,  and  are  then  as- 
sumed to  be  further  reduced  far  beyond  the  limits  of  repre- 
sentation. So  that  this  rhythmically-moving  molecule, 
which  is  our  unit  of  composition  of  external  phenomena,  is 
mental  in  a  three-fold  sense — our  experiences  of  a  rhythmi- 
cally-moving mass,  whence  the  conception  of  it  is  derived, 
are  states  of  mind,  having  objective  counterparts  that  are 
unknown;  the  derived  conception  of  a  rhythmically-moving 
molecule,  is  formed  of  states  of  mind  that  have  no  directly- 
presented  objective  counterparts  at  all ;  and  when  we  try  to 
think  of  the  rhythmically-moving  molecule  as  we  suppose  it 
to  exist,  we  do  so  by  imagining  that  we  have  re-represented 
these  representative  states,  on  an  infinitely-reduced  scale. 
So  that  the  unit  out  of  which  we  build  our  interpretation  of 
material  phenomena,  is  triply  ideal. 

On  the  other  hand,  what  are  we  to  think  of  this  ideal 
unit,  considered  as  a  portion  of  Mind?  It  arises,  as  we 
have  seen,  by  synthesis  of  many  feelings,  real  and  ideal, 
and  of  the  many  changes  among  them.  What  are  feelings? 
What  is  changed?     And  what  changes  it?     If  to  avoid 


626  PHYSICAL  SYNTHESIS. 

obvious  implications  of  a  materiality,  we  call  each  element 
of  this  ideal  unit,  a  state  of  consciousness,  we  only  get  into 
other  similar  implications.  The  conception  of  a  state  of 
consciousness  implies  the  conception  of  an  existence  which 
has  the  state.  When  on  decomposing  certain  of  our  feelings 
we  find  them  formed  of  minute  shocks,  succeeding  one  an- 
other with  different  rapidities  and  in  different  combinations; 
and  when  we  conclude  that  all  our  feelings  are  probably 
formed  of  such  units  of  consciousness  variously  combined, 
we  are  still  obliged  to  conceive  this  unit  of  consciousness 
as  a  change  wrought  by  some  force  in  something.  No  ef- 
fort of  imagination  enables  us  to  think  of  a  shock,  however 
minute,  except  as  undergone  by  an  entity.  We  are  com- 
pelled, therefore,  to  postulate  a  substance  of  Mind  that  is 
affected,  before  we  can  think  of  its  affections.  But  we  can 
form  no  notion  of  a  substance  of  Mind  absolutely  divested 
of  attributes  connoted  by  the  word  substance;  and  all  such 
attributes  are  abstracted  from  our  experiences  of  material 
phenomena.  Expel  from  the  conception  of  Mind  every  one 
of  those  attributes  by  which  we  distinguish  an  external 
something  from  an  external  nothing,  and  the  conception  of 
Mind  becomes  nothing.  If  to  escape  this  difl&culty  we  re- 
pudiate the  expression  "  state  of  consciousness,"  and  call 
each  undecomposable  feeling  "  a  consciousness,"  we  merely 
get  out  of  one  difficulty  into  another.  A  consciousness,  if 
not  the  state  of  a  thing  is  itself  a  thing.  And  as  many  dif- 
ferent consciousnesses  as  there  are,  so  many  different  things 
there  are.  How  shall  we  think  of  these  so  many  independ- 
ent things,  having  their  differential  characters,  when  we 
have  excluded  all  conceptions  derived  from  external  phe- 
nomena? We  can  think  of  entities  that  differ  from  one  an- 
other and  from  nonentity,  only  by  bringing  into  our  thoughts 
the  remembrances  of  entities  which  we  distinguished  as  ob- 
jective and  material.  Again,  how  are  we  to  conceive  these 
consciousnesses  as  either  being  changed  one  into  another 


RESULTS.  637 

or  as  being  replaced  one  by  another?  We  cannot  do  this 
without  conceiving  of  cause ;  and  we  know  nothing  of  cause 
save  as  manifested  in  existences  we  class  as  material — either 
our  own  bodies  or  surrounding  things. 

See  then  our  predicament.  We  can  think  of  Matter  only 
in  terms  of  Mind.  We  can  think  of  Mind  only  in  terms  of 
Matter.  When  we  have  pushed  our  explorations  of  the 
first  to  the  uttermost  limit,  we  are  referred  to  the  second 
for  a  final  answer;  and  when  we  have  got  the  final  answer 
of  the  second  we  are  referred  back  to  the  first  for  an  inter^ 
pretation  of  it.  We  find  the  value  of  x  in  terms  of  y;  then, 
we  find  the  value  of  y  in  terms  of  x;  and  so  on  we  may  con- 
tinue for  ever  without  coming  nearer  to  a  solution.  The 
antithesis  of  subject  and  object,  never  to  be  transcended 
while  consciousness  lasts,  renders  impossible  all  knowledge 
of  that  Ultimate  Reality  in  which  subject  and  object  are 
united. 

§  273.  And  this  brings  us  to  the  true  conclusion  implied 
throughout  the  foregoing  pages — the  conclusion  that  it  is 
one  and  the  same  Ultimate  Reality  which  is  manifested  to 
us  subjectively  and  objectively.  For  while  the  nature  of 
that  which  is  manifested  under  either  form  proves  to  be 
inscrutable,  the  order  of  its  manifestations  throughout  all 
mental  phenomena  proves  to  be  the  same  as  the  order  of  its 
manifestations  throughout  all  material  phenomena. 

The  Law  of  Evolution  holds  of  the  inner  world  as  it  does 
of  the  outer  world.  On  tracing  up  from  its  low  and  vague 
beginnings  the  intelligence  which  becomes  so  marvellous 
in  the  highest  beings,  we  find  that  under  whatever  aspect 
contemplated,  it  presents  a  progressive  transformation  of 
like  nature  with  the  progressive  transformation  we  trace  in 
the  Universe  as  a  whole,  no  less  than  in  each  of  its  parts. 
If  we  study  the  development  of  the  nervous  system,  we  see  it 
advancing  in  integration,  in  complexity,  in  definiteness.    If 


628  PHYSICAL  SYNTHESIS. 

we  turn  to  its  functions,  we  find  these  similarly  sliow  an  ever- 
increasing  inter-dependence,  an  augmentation  in  number 
and  heterogeneity,  and  a  greater  precision.  If  we  examine 
the  relations  of  these  functions  to  the  actions  going  on  in  the 
world  around,  we  see  that  the  correspondence  between  them 
progresses  in  range  and  amount,  becomes  continually  more 
complex  and  more  special,  and  advances  through  differenti- 
ations and  integrations  like  those  everywhere  going  on.  And 
when  we  observe  the  correlative  states  of  consciousness,  we 
discover  that  these,  too,  beginning  as  simple,  vague,  and 
incoherent,  become  increasingly-numerous  in  their  kinds, 
are  united  into  aggregates  which  are  larger,  more  multitudi- 
nous, and  more  multiform,  and  eventually  assume  those 
finished  shapes  we  see  in  scientific .  generalizations,  where 
definitely-quantitative  elements  are  co-ordinated  in  defi- 
nitely-quantitative relations. 

Such  are  the  results  of  a  synthesis  which  we  shall  pre- 
sently find  verified  by  analysis.  These  are  the  conclusions 
to  which  Objective  Psychology  has  brought  us;  and  these 
are  the  conclusions  to  which  we  shall  find  ourselves  led  by 
that  Subjective  Psychology  to  which  we  now  pass. 


APPENDIX. 


APPEOT)IX. 


ON  THE  ACTIONS  OP  ANESTHETICS  AND  NARCOTICS. 


While  omitting  tliem  from  the  text,  I  cannot  refrain  from  here 
appending  certain  conclusions  respecting  the  actions  of  Anaesthetics 
and  Narcotics,  to  which  I  have  been  led  while  seeking  an  explanation 
of  the  anomalies  referred  to. 

It  is  commonly  supposed  that  these  agents  have  special  relations 
to  nervous  tissue,  rather  than  to  other  tissues ;  and,  because  of  the 
different  effects  they  work,  it  is  even  assumed  that  some  of  them 
have  elective  affinities  for  the  matter  composing  certain  nervous 
centres  rather  than  for  that  composing  others.  This  last  supposi- 
tion, made  without  other  warrant  than  that  it  renders  certain  of  the 
facts  intelligible,  must  be  carried  much  further  to  account  for  all  the 
facts.  As  the  same  anaesthetic  does  not  act  in  the  same  way  on  all 
persons,  but  here  affects  one  centre  more  and  here  another,  it  must 
be  assumed  that  the  chemical  compositions  of  these  centres  are  in 
such  cases  interchanged — nay,  as  one  drunken  man  becomes  morose 
while  another  becomes  affectionate,  it  must  be  supposed  that  different 
parts  of  the  cerebral  hemispheres  have  in  such  cases  interchanged 
their  chemical  compositions.  Nor  is  even  this  the  extreme  of  the 
diflSculty.  For  since  in  the  same  individual,  the  same  quantity  of 
the  same  ansesthetic  will  produce  quite  different  effects  in  different 
states  of  the  circulation ;  the  hypothesis  requires  us  to  suppose  that 
these  contrasts  of  chemical  composition  among  the  nervous  centres 
interchange  from  hour  to  hour. 

If  instead  of  a  gratuitous  assumption  that  leaves  many  of  the  effects 
unaccounted  for,  we  make  an  assumption  that  is  not  gratuitous  and 
renders  the  facts,  general  and  special,  intelligible,  there  cannot  be  a 
doubt  which  of  the  two  is  preferable.  Setting  out,  then,  with  the 
generalization  that  these  various  substances  that  affect  the  nervous 
system — the  vegeto-alkalies,  the  alcohols  and  ethers,  nitrous  oxide, 
ammonia,  arsenic,  the  mineral  acids,  &c. — are  substances  that  pro- 
duce changes  in  albuminous  matters,  let  us  consider  how  their 
respective  effects  will  be  modified  by  the  various  conditions  under 
which  they  act.  Agents  having  powerful  affinities  for  components  of 
the  tissues  and  fluids,  given  in  small  quantities  to  avoid  destruction 

«81 


632  APPENDIX. 

of  the  membranes,  can  scarcely  reach  the  nervous  system  in  uncom- 
bined  states ;  and  may  be  expected  to  work  their  respective  effects 
through  the  instrumentalities  of  the  compounds  they  have  formed. 
The  most  conspicuous  effects  will  be  wrought  by  those  agents 
which,  while  they  can  produce  molecular  changes  in  albuminous 
substances,  have  not  such  powerful  aflBnities  for  them,  or  for  their 
elements,  as  to  be  arrested  on  their  way  to  the  nervous  system.  The 
anaesthetics  and  narcotics  may  fairly  be  regarded  as  fulfilling  this 
requirement.  So  much  being  premised,  let  us  ask  what  will  be  the  in- 
fluences of  such  substances  carried  indiscriminately  through  the  body 
and  acting  indiscriminately  on  the  tissues.  If  a  blood- corpuscle,  or 
a  bile-cell,  or  a  particle  of  mucous  membrane,  is  affected  by  ether 
or  by  opium,  and  changed  isomerically  or  otherwise,  the  implied 
molecular  disturbance  works  little  or  no  effect  on  the  body  at  large, 
in  the  absence  of  a  channel  through  which  the  disturbance  can  be 
conducted.  But  if  the  ether  or  opium  affects  a  molecule  of  a 
nerve-corpuscle,  the  line  of  isomerically-changing  molecules  con- 
nected with  the  nerve-corpuscle,  conveys  the  disturbance  to  some 
remote  place ;  whence,  by  diffusion  and  re-diffusion,  it  is  carried 
through  the  nervous  system  as  a  whole.  That  is  to  say,  we  need 
not  suppose  the  anaesthetic  or  narcotic  to  have  more  aflBnity  for 
the  protein-substance  of  nerve-corpuscle  or  nerve-fibre,  than  for  the 
other  forms  of  protein-substance  it  comes  in  contact  with ;  but  its 
effect  is  comprehensible  as  resulting  from  the  structural  relations  of 
nerve-corpuscle  and  nerve-fibre. 

Carrying  with  us  this  conception,  and  not  assuming  that  the 
anaesthetic  or  narcotic  has  any  elective  aflSnity  for  the  matter  of  one 
nerve-corpuscle  rather  than  for  that  of  another,  or  for  nerve-cor- 
puscle rather  than  for  nerve-fibre,  let  us  consider  what  further  dif- 
ferences in  its  actions  will  be  entailed  by  further  differences  in  the 
conditions  of  the  parts.  We  have  experimental  proof  that  an  agent 
which  arrests  the  function  of  nerve,  serves  at  the  moment  of  its 
action  to  excite  nerve.  If  nerve  is  cut  in  two,  or  constricted  by  a 
ligature,  or  seared,  or  touched  by  a  powerful  acid,  it  is,  in  the  act 
of  being  incapacitated,  made  to  convey  a  strong  discharge.  We 
have  reason  to  expect,  then,  that  whatever  agent  so  acts  on  nerve- 
substance  as  to  disable  it,  will,  in  working  the  implied  molecular 
change,  cause  a  molecular  disturbance  constituting  excitement.  To 
understand  fully,  however,  why  stimulation  precedes  narcosis,  we 
must  observe  the  different  relations  of  nerve-corpuscles  and  nerve- 
fibres  to  the  blood. 

As  pointed  out  when  treating  of  the  nervous  system,  its  vesicular 
tissue  is  far  more  vascular  than  its  fibrous  tissue ;  and  further, 
while  the  matter  of  nerve- vesicles  is  so  arranged  as  to  offer  the  least 
possible  obstacle  to  the  reception  of  fluid  from  the  adjacent 
capillaries,  the  matter  of  nerve-fibres  is  shielded  by  a  medullary 


APPENDIX.  633 

sheath.  Hence,  when  any  agent  capable  of  so  changing  the  mole- 
cular state  of  nerve-matter  as  to  arrest  its  function,  is  carried  into 
the  blood,  it  first  acts  on  the  nerve-corpuscles.  Each  change  produced 
in  one  of  these  (be  it  the  decomposition  of  a  molecule  or,  as  is  more 
probable,  the  isomeric  transformation  of  a  molecule)  implies  a  disen- 
gagement of  molecular  motion,  that  is  immediately  propagated  along 
the  connected  nerve-fibres,  and  excites  the  parts  to  which  they  run. 
Every  nerve-corpuscle  being  thus  quickly  acted  upon,  and  emitting 
success]  ve  discharges  as  the  successive  molecular  transformations  are 
wrought  in  it,  there  results  a  general  exaltation  of  state ;  as  shown 
physically  in  the  invigorated  pulse  and  contractions  of  the  muscles, 
and  as  shown  psychically  in  the  rush  of  vivid  ideas  and  intensified 
feelings.  But  what  is  taking  place  with  the  rest  of  the  nervous 
system  ?  While  some  molecules  of  alcohol  or  ether  or  chloroform, 
as  the  case  may  be,  have  thus  quickly  passed  from  the  closely- 
adjacent  capillaries  into  the  almost  naked  matter  of  the  nerve- 
corpuscles,  other  such  molecules  are  elsewhere  on  their  way  through 
the  outer  coats  of  the  nerve-tubes  and  the  medullary  sheaths  within 
these ;  and  they  presently  reach  the  bundle  of  fibrillae  forming  the 
axis- cylinders.  It  may  be  concluded  that  the  isomeric  changes 
they  immediately  begin  to  produce  in  these,  at  first  add  to  the 
general  excitement.  Though  each  molecule  changed  is  thereafter 
incapacitated  for  taking  part  in  the  transfer  of  a  nerve-wave ;  yet 
in  the  act  of  being  changed,  it  becomes  itself  the  initiator  of  a 
nerve-wave.  Be  this  as  it  may,  however,  we  must  infer  that  as  the 
anaesthetic  invades  a  nerve-fibre  more  and  more,  a  greater  and 
greater  number  of  its  molecules  are  rendered  unable  to  transfer  a 
wave  of  the  peculiar  isomeric  change  which  constitutes  a  nervous 
discharge ;  and,  eventually,  the  fibre  becomes  impermeable. 

Observe,  now,  the  several  implications.  We  have  first  an  explana- 
tion of  the  fact  that,  other  things  being  equal,  the  longer  nerve- 
flbres  become  impermeable  sooner  than  the  shorter.  Assuming,  as 
we  may  fairly  do,  that  all  the  nerves  conveying  sensations  of  touch 
are  equally  permeable,  it  will  naturally  happen  that  at  the  expira- 
tion of  a  given  interval,  the  probability  that  a  nerve- fibre  has  been 
at  some  part  of  its  course  invaded  by  the  anaesthetic,  will  be  greater 
if  the  fibre  is  long  than  if  it  is  short.  Hence  the  fact  that  anaes- 
thesia occurs  first  in  the  hinder  extremities ;  and  that  parts  of  the 
surface  nearer  to  the  nervous  centres  lose  their  sensibility  later.* 

We  are  enabled  also  to  account  for  those  diversities  of  results 
produced  by  different  doses  and  by  the  same  dose  under  different 
conditions.  Reaching  easily  the  vesicular  elements  of  the  nervous 
system,  and  with  more  diflSculty  the  fibrous  elements,  a  small 

•  It  is  true  that,  according  to  Dr.  Anstie,  dogs  and  rats  experimented  upon, 
early  lose  sensation  in  the  muzzle ;  but  here  the  natural  ansesthesia  due  to  the 
coldiaesa  caused  by  constant  evaporation,  aids  the  artificial  ansesthesia. 


634r  APPENDIX 

quantity  of  one  of  these  substances  introduced  into  the  blood,  will 
have  a  stimulating  effect  little  if  at  all  qualified  by  the  anaesthetic 
effect.  Obviously,  too,  the  conflict  between  these  opposite  actions 
— the  one  tending  to  increase  the  genesis  of  nervous  fluid  and  the 
other  tending  to  block  up  the  channels  for  its  discharge — will, 
other  things  equal,  end  in  predominance  of  the  one  or  the  other 
according  to  the  state  of  the  circulation,  general  or  local.  If  the 
blood  is  rapidly  propelled,  so  as  to  bring  to  the  nervous  centres  an 
abundant  supply  not  only  of  the  exciting  agent  but  of  the  materials 
which  further  waste  and  repair,  the  increased  amount  of  nervous 
fluid  generated,  may  more  than  compensate  for  decrease  in  the 
facility  of  its  transfer  along  the  nerves ;  and  this  may  especially  be 
expected  to  happen  where,  in  addition  to  an  active  general  circula- 
tion, the  circulation  through  the  brain  as  a  whole,  or  through  some 
of  its  plexuses,  is  much  exalted.  On  the  other  hand,  as  the  anaes- 
thetic, once  diffused  through  the  system,  will  invade  the  nerve-fibres 
in  much  the  same  way  whether  the  blood  moves  slowly  or  quickly, 
there  will,  when  it  moves  slowly,  result  an  impediment  to  nervous 
discharge  without  any  augmented  pressure  of  nervous  fluid,  and 
hence  the  sedative  influence  will  predominate.  The  contrasts  be- 
tween different  persons,  and  different  states  of  the  same  person,  as 
affected  by  these  agents,  thus  become  intelligible. 

"  But  how  are  we  to  explain  the  unlike  effects  produced  on  the 
nervous  system  by  unlike  agents  ?  Should  not  all  anaesthetics  and 
narcotics  have  the  same  effects  ? "  I  reply  in  the  first  place,  that 
much  as  these  various  agents,  swallowed  or  inhaled  or  injected, 
differ  in  their  minor  results,  they  do  agree  in  their  major  results,  as 
being  excitants  or  sedatives  according  to  circumstances,  and  as 
habitually  producing  exaltation  of  function  before  depression  of 
function,  when  the  dose  is  suflScient  to  produce  depression.  In  the 
second  place,  I  reply  that  while  there  are  doubtless  many  more 
special  causes  of  differences  in  their  actions,  there  is  one  qonspicu- 
ous  general  cause — their  greater  or  less  molecular  mobility,  and  con- 
sequent greater  or  less  diffusibility  through  the  tissues.  From  this 
arises  the  generic  contrast  between  the  actions  of  anaesthetics 
and  narcotics.  As  compared  with  the  vegeto-alkalies,  &c.,  the 
alcohols,  ethers,  &c.,  are  substances  of  much  lower  molecular  com- 
plexity, which  show  by  their  readiness  to  assume  the  gaseous  form 
how  much  more  diffusible  they  are.  Bearing  in  mind  the  researches 
of  Prof.  Graham,  we  may  fairly  infer  that  molecules  of  nitrous 
oxide,  or  ether,  or  chloroform,  pass  through  the  walls  of  the  blood- 
vessels and  the  protective  coats  of  the  nerve-fibres,  much  more 
rapidly  than  do  molecules  of  morphia,  or  of  that  component  to 
which  hashish  owes  its  power.  And  if  so,  it  must  naturally  happen 
that  while  the  stimulant  effects  of  the  anaesthetics  will  be  very 
quickly  shown  and  soon  followed  by  the  paralyzing  effects,  the 


APPENDIX.  636 

stimulant  effects  of  the  narcotics,  less  quickly  shown,  will  be  less 
quickly  followed  by  the  paralyzing  effects.  It  may  be  suspected, 
too,  that  among  the  anaesthetics  themselves  and  among  the  nar- 
cotics themselves,  many  such  unlikenesses  of  action  must  result 
from  unlikenesses  of  diffusibility.  Indeed,  suspicion  rises  almost 
to  certainty  on  remembering  how  the  most  diffusible  anaesthetics 
not  only  rapidly  act  but  rapidly  cease  to  act,  in  consequence  of 
their  speedy  elimination  from  the  system. 

It  is  quite  possible,  then,  that  the  various  effects  worked  by  thesw 
various  agents,  all  result  from  specialities  of  co-operation  among  the 
many  factors.  Let  me  briefly  enumerate  these  factors: — 1.  The 
place  at  which  the  agent  is  absorbed,  and  the  consequent  ability  of 
the  agent  to  act  on  some  parts  of  the  nervous  system  sooner  than  on 
others.  2.  The  rapidity  of  absorption ;  which,  if  great,  will  make 
possible  a  marked  local  effect  before  a  marked  general  effect.  3.  The 
quantity  absorbed,  as  suflBcient  to  act  on  nerve-vesicle  without 
appreciably  affecting  nerve-fibre,  or  as  suflBcient  to  appreciably 
affect  both.  4.  The  relative  molecular  mobility  of  the  agent. 
5.  Its  chemical  relations  to  the  blood,  (a)  as  affecting  its  power 
of  carrying  gases,  (6)  as  affecting  its  various  components  in  such 
ways  as  to  aid  or  hinder  waste  or  nutrition.  6.  Its  chemical 
relations  to  the  substances  passed  through  (more  especially  to  the 
medullary  substance  covering  nerve-fibre)  which  will  aid  or  hinder 
its  paralyzing  effect.  7.  The  general  state  of  the  circulation. 
8.  The  state  of  the  circulation  in  each  nervous  centre,  as  ordinary 
or  as  excited  by  function.  9.  The  characters  of  the  nerve-fibres 
acted  upon,  as  differing  (a)  in  length,  (b)  in  ability  to  convey 
discharges  with  facility,  (c)  in  amount  of  protective  covering,  (d) 
in  proximity  to  many  or  few  capillaries.  Here,  then,  are  a  dozen 
factors,  the  co-operation  of  which  will  not  be  the  same  in  any  two 
cases ;  and  unlike  primary  combinations  of  them  may  cause  end- 
lessly-varied secondary  combinations — as  when,  for  example,  the 
vaso-motor  nerves  of  one  centre  are  acted  on  sooner  than  on  those 
of  another,  thus  complicating  the  effects  by  altering  the  relative 
supplies  of  blood  to  these  centres.  It  is  not  necessary,  then,  to 
assign  elective  aflBnities  for  special  centres  as  the  only  possible 
causes  of  the  special  effects.  This  hypothesis  should,  I  think,  be 
resorted  to  only  when  other  modes  of  interpretation  are  proven 
inadequate. 


CONSCIOUSNESS  UNDER  CHLOROFORM. 

A  University  graduate  whose  studies  in  Psychology  and  Philo- 
sophy have  made  him  an  observer  able  to  see  the  meanings  of  his 
experiences,  has  furnished  me  with  the  following  account  of  the 
feelings  and  ideas  that  arose  in  him  during  loss  of  consciousness  and 
during  return  to  consciousness.  My  correspondent,  describing 
himself  as  extremely  susceptible  to  female  beauty,  explains  that 
"  the  girl "  named  in  the  course  of  the  description  was  an  unknown 
young  lady  in  the  railway  carriage  which  brought  him  up  to  town 
to  the  dentist's.  He  says  his  system  resisted  the  influence  of 
chloroform  to  such  a  degree,  that  it  took  twenty  minutes  to  produce 
insensibility :  the  result  being  that  for  a  much  longer  time  than 
usual  he  underwent  partial  hyperaesthesia  instead  of  anaesthesia. 
After  specifying  some  dreadful  sensations  which  soon  arose  he  goes 
on  to  say : —  «  ♦  ♦  j  began  to  be  terrified  to  such 
a  wonderful  extent  as  I  would  never  before  have  guessed  possible. 
I  made  an  involuntary  effort  to  get  out  of  the  chair,  and  then — 
suddenly  became  aware  •  that  I  was  looking  at  nothing :  while 
taken  up  by  the  confusion  in  my  lungs,  the  outward  things  in  the 
room  had  gone,  and  I  was  "  alone  in  the  dark."  I  felt  a  force  on 
my  arm  (which  did  not  strike  me  as  the  surgeon's  "  hand,"  but  merely 
as  an  external  restraint)  keeping  me  down,  and  this  was  the  last 
straw  which  made  me  give  in,  the  last  definite  thing  (smell,  sound, 
sight,  or  touch)  I  remembered  outside  my  own  body.  Instantly  I 
was  seized  and  overwhelmed  by  the  panic  inside.  I  could  feel 
every  air-cell  struggling  spasmodically  against  an  awful  pressure. 
In  their  struggle  they  seemed  to  tear  away  from  one  another  in  all 
directions,  and  there  was  universal  racking  torture,  while  meantime 
the  common  foe,  in  the  shape  of  this  iron  pressure,  kept  settling 
down  with  more  and  more  irresistible  might  into  every  nook  and 
crevice  of  the  scene.  My  consciousness  was  now  about  this :  I  was 
not  aware  of  anything  but  an  isolated  scene  of  torture,  pervaded  by 
a  hitherto  unknown  sense  of  terror  (and  by  what  I  have  since  learnt 
is  called  "  the  unity  of  consciousness : "  this  never  deserted  the 
scene,  even  down  to  the  very  last  inaudible  heart-beat).  Yet  I  call 
it  a  "  scene,"  because  I  recognized  some  different  parts  of  my  body, 
and  felt  that  the  pain  in  one  part  was  not  the  same  as  that  in 
another.  Meanwhile,  along  with  the  increased  intensity  of  convul- 
sion in  my  lungs,  an  element  of  noise  had  sprung  up.  A  chaotic 
roaring  ran  through  my  brain,  innumerable  drums  began  to  beat  far 
inside  my  ear,  till  the  confusion  presently  came  to  a  monstrous 


APPENDIX,  637 

ttudding,  every  thud  of  wMch  wounded  me  like  a  club  falling 
repeatedly  on  the  same  spot.         «         »         * 

From  this  stage  my  lungs  ceased  to  occupy  me,  and  I  forget  how 
the  struggle  finished.  There  was  a  sense  of  comparative  relief  that, 
at  any  rate,  one  force  was  victorious,  and  the  distraction  over ;  the 
strange  large  fright  that  had  seized  me  so  entirely  when  I  felt 
myself  ensnared  into  dark  suffocation  was  now  gone  also,  and  there 
was  only  left  the  huge  thudding  at  my  ears,  and  the  terribly 
impetuous  stroke  of  my  heart.  The  thudding  gradually  got  less 
acutely  painful,  and  less  loud ;  I  remember  a  recognition  of  satis- 
faction that  one  more  fearful  disturbance  was  gone.  But,  while  the 
thunder  in  my  ear  was  thus  growing  duller,  all  of  a  sudden  my 
heart  sprang  out  with  a  more  vivid  flash  of  sensation  than  any  of 
those  previous  ones.  The  force  of  an  express  engine  was  straining 
there,  and  like  a  burning  ball  it  leapt  from  side  to  side,  faster  and 
faster,  hitting  me  with  such  a  superhuman  earnestness  that  I  felt 
each  time  as  if  the  iron  had  entered  my  soul,  and  it  was  all  over  with 
me  for  ever.  (Not  that  "  I "  was  now  any  more  than  this  burning- 
hot  heart  and  the  walled  space  in  which  it  was  making  its  strokes : 
the  rest  of  "  me "  had  gone  unobserved  out  of  focus.)  Every 
stroke  produced  exquisite  pain  on  the  flesh  against  which  it  beat 
glowing,  and  there  was  a  radiation,  as  from  a  molten  lump  of  metal 
between  enclosures.  Presently  the  unbearable  heat  got  less,  and 
there  was  nothing  remaining  except  a  pendulous  movement, 
slackening  speed,  and  not  painful.  Of  nothing  beyond  was  I 
conscious  but  this  warm  body  vibrating :  not  a  single  other  part  of 
me  was  left,  and  there  was  not  a  single  other  movement  of  any  sort 
to  attract  my  attention.  A  fading  sense  of  infinite  leisure  at  last, 
in  a  dreamy  inaudible  air ;  then  all  was  hushed  out  of  notice. 

*  *  There  was  the  breaking  of  a  silence  that  might  have 
been  going  on  for  ever  in  the  utterly  dark  air.  An  undisturbed 
empty  quiet  was  everywhere,  except  that  a  stupid  presence  lay  like 
a  heavy  intrusion  somewhere, — a  blotch  on  the  calm.  This  blotch 
became  more  inharmonious,  more  distinctly  leaden ;  it  was  a  heavier 
pressure, — it  is  actually  intruding  further, — and  before  almost  there 
was  time  to  wonder  feebly  how  disagreeable  was  this  interruption 
of  untroubled  quiet,  it  had  loomed  out  as  something  unspeakably 
cruel  and  woeful.  For  a  bit  there  was  nothing  more  than  this 
profoundly  cruel  presence,  and  my  recognition  *  of  it.  It  seemed 
unutterably  monstrous  in  its  nature,  and  I  felt  it  like  some  super- 
human injustice ;  but  so  entire  had  been  the  still  rest  all  round 
before  its  shadow  troubled  me,  that  I  had  no  notion  of  making  the 
faintest  remonstrance.  *  *  *  It  got  worse.  *  «  * 
Just  as  the  cruelty  and  injustice  became  so  unbearable  that  I  hardly 

•  If  there  were  a  noun  belonging  to  the  verb  "  To  be  aware  of,"  like 
"  recognition  "  to  "  recognize,"  it  would  be  the  one  to  use  here. 


638  APPENDIX. 

could  take  it  in,  suddenly  it  came  out  a  massive,  pulsating  pain^ 
and  I  was  all  over  one  tender  wound,  with  this  dense  pain  probing 
me  to  my  deepest  depths.  I  felt  one  sympathetic  body  of  atoms, 
and  at  each  probe  of  the  pain  every  single  atom  was  forced  by  a 
tremendous  pressure  into  all  the  rest,  while  everyone  of  them  was 
acutely  tender,  and  shrank  from  the  wound — only  there  was  nowhere 
to  shrink.  A  little  before,  I  had  merely  felt  the  cruel  element,  in 
helpless  passivity  ;  now,  a  still  more  crushing  probe  came ;  for  an 
instant  it  forced  all  my  atoms  into  one  solid  steel-mass  of  intense 
agony — then,  when  things  couldn't  go  much  further,  and  all  must 
be  over,  a  sense  of  reaction  emerged ;  there  was  a  loosening,  and  I 
was  urged  into  relief  by  uttering  from  my  very  depths,  what  seemed 
not  so  much  (at  first)  a  piteous  remonstrance  as  a  piteous  "  express- 
ion "  (like  an  imitation)  of  the  pain :  in  fact,  the  sense  of  woe  had  got 
also  outside,  and  I  heard  it,  a  very  low,  infinitely  genuine,  moan. 
*  *  The  next  second  there  was  a  change :  hitherto  it  had  been 
pain  partout — now  there  came  a  quick  concentration,  the  pain  all  ran 
together  (like  quicksilver),  and  I  suddenly  was  aware  that  it  was 
(localized)  up  on  the  right ;  while,  simultaneously  with  this  recogni- 
tion of  locality,  a  feeling  of  incipient  resistance  began  to  be  in  other 
parts  (not  that  I  felt  them  except  just  as  other  parts)  of  me  from 
which  the  pain  had  receded.  The  pain  itself  was  no  less  intense, 
rather  more  vivid,  only  I  seemed  to  take  it  in  a  more  lively  manner: 
my  uttering  of  a  moan  was  no  longer  a  mere  faithful  representation 
out  into  the  air  of  what  was  inside  me,  but  I  had  a  slight  sense  of 
making  an  appeal  for  sympathy :  to  whom  or  to  what  I  did  not  know, 
for  there  was  no  one  or  anything  there.  I  was  just  going  to  utte^ 
a  yet  louder  moan — as  a  fresh  fearful  imposition  of  force  plunged 
into  me — when,  there  in  front  of  me,  to  the  left  of  my  pain,  was 
that  girl,  with  those  lovely  ankles,  and  the  graceful  Zingari  brown 
stockings.  *  »  j  ^qX^^  as  distinctly  as  if  some  had  told  me 
aloud,  that  I  would  not  make  any  cry,  that  it  was  not  the  thing. 

Now  came  an  agonizing  cold  wrench,  and  two  or  three  more 
successively,  in  such  a  hideously  rough  fashion,  that  the  girl  went, 
and  everything  was  tortured  out  of  me  but  the  darkness  and  the 
gigantic  racking  swaying  torture  which  was  excruciating  my  right 
side.  An  iron  force  like  a  million-horsepower  had  hold  of  me,  and 
I  was  being  pulled  upwards  and  out  of  where  I  was,  while  I  myself 
seemed  another  million-horsepower  which  would  not  be  pulled :  the 
pain  was  something  to  be  remembered.  But  up  I  came,  the  dark- 
ness got  denser  (I  went  so  fast)  ;  it  was  vibrating,  the  dense  agony 
vibrated  faster ;  /  was  quivering,  struggling,  kicking  out ;  every- 
thing was  a  convulsion  of  torture,  my  head  seemed  to  come  to  the 
surface,  a  glimpse  of  light  and  air  broke  on  the  darkness,  voices 
came  through  to  me,  and  words;  I  recognized  that  a  "  tooth  "  was 


APPENDIX.  689 

being  slowly  twisted  out  of  my  jaw,  then  I  groaned  imploringly,  in 
true  earthly  style,  as  if  this  was  too  much,  and  I  ought  to  be  let 
alone  now  I  was  getting  my  *'  head  "  out ;  then  I  swallowed  in 
air,  made  an  exertion  with  my  "  chest,"  found  my  "  arms  "  were 
pressing  something  hard,  grasped  the  "  chair,"  and  pushed  myself 
up  out  in  bewildered  light,  just  as  the  dentist  threw  away  the 
second  right  molar  from  the  upper  jaw. 

Concerning  this  account  it  may  be  remarked,  on  the  one  hand, 
that  the  higher  consciousness  seems  not  to  have  been  wholly 
abolished  ;  since  there  remained  certain  emotions  and  certain  most 
general  ideas  of  relation  to  objective  agents.  On  the  other  hand 
it  is  to  be  doubted  whether  the  partial  consciousness  which  the 
narrator  had  during  anaesthesia,  is  not,  in  the  description,  eked  out 
in  some  measure  by  the  ideas  of  his  recovered  consciousness  carried 
back  to  them.  Be  this  as  it  may,  however,  it  is  clear  that  certain 
components  of  consciousness  disappeared  and  others  became 
extremely  vague,  while  a  remainder  continued  tolerably  distinct. 
And  there  is  much  significance  in  the  relations  among  them  : — 
1.  There  ceased  earliest  the  sensations  derived  from  the  special 
senses ;  then  the  impression  of  force  acting  on  the  body  from 
without ;  and,  simultaneously,  there  ceased  the  consciousness  of 
external  space-relations.  2.  There  remained  a  vague  sense  of  rela- 
tive position  within  the  body ;  which,  gradually  fading,  left  at  last 
only  a  sense  of  those  space-relations  implied  by  consciousness  of  the 
heart's  pulsations.  3.  And  this  cluster  of  related  sensations 
produced  by  the  heart's  action,  finally  constituted  the  only  remain- 
ing distinct  portion  of  the  ^170.  4.  In  the  returning  consciousness 
we  note  first  a  sense  of  pressure  somewhere :  there  was  no  con- 
sciousness of  space-relations  within  the  body.  5 .  The  consciousness 
of  this  was  not  a  cognition  proper.  In  an  accompanying  letter  my 
correspondent  says  of  it : — "  *  Recognition '  seems  to  imply  install- 
ation in  some  previously-formed  concept  (talking  in  the  Kantian 
way),  and  this  is  just  what  was  not  the  case : "  that  is,  consciousness 
was  reduced  to  a  state  in  which  there  was  not  that  classing  of 
states  which  constitutes  thought.  6.  The  pain  into  which  the 
pressure  was  transformed  was  similarly  universal  instead  of  local. 
7.  When  the  pain  became  localized,  its  position  in  space  was 
vague :  it  was  "  up  on  the  right."  8.  Concerning  the  apparition 
of  "  the  girl,"  which,  as  my  correspondent  remarks,  seems  to  have 
occurred  somewhat  out  of  the  probable  order,  he  says,  in  a  letter : 
— *'  I  did  not  recognize  her  '  under  any  concept ' — what  I  saw 
seemed  to  be  almost  unassisted  intuition  in  the  Kantian  sense." 
9.  The  localization  of  the  pain  was  at  first  the  least  possible — the 
consciousness  was  of  that  part  versus  all  other  parts  unlocalized. 

These  experiences  furnish  remarkable  verifications  of  certain 
48 


640  APPENDIX. 

doctrines  set  forth  in  this  work.  This  degradation  of  consciousness 
by  chloroform,  abolishing  first  the  higher  faculties  and  descending 
gradually  to  the  lowest,  may  be  considered  as  reversing  that 
ascending  genesis  of  consciousness  which  has  taken  place  in  the 
course  of  evolution ;  and  the  stages  of  descent  may  be  taken  as 
showing,  in  opposite  order,  the  stages  of  ascent.  It  is  significant, 
therefore,  that  impressions  from  the  special  senses  ceasing  early, 
leave  behind  as  the  last  impression  derived  from  without,  the  sense 
of  outer  force  conceived  as  opposed  by  inner  resistance ;  for  this  we 
saw  to  be  the  primordial  element  of  consciousness.  (§  347.)  Again, 
the  fact  that  the  consciousness  of  external  space  disappeared  simul- 
taneously with  the  consciousness  of  external  force,  answers  to  the 
conclusion  drawn  that  space-ideas  are  built  out  of  experiences  of 
resistant  positions,  the  relations  among  which  are  measured  by 
sensations  of  muscular  efiEort.  (§  §  343,  348.)  Further  there  is 
meaning  in  the  fact  that  a  vague  sense  of  relative  position  within 
the  body  survived ;  since  we  concluded  that  by  mutual  exploration 
there  is  gained  that  knowledge  of  the  relations  among  the  parts 
of  the  body,  which  gives  measures  through  which  the  developed 
knowledge  of  surrounding  space  is  reached.  (§  §  344,  345.)  Once 
more  we  get  evidence  that  the  Ego  admits  of  being  progressively 
shorn  of  its  higher  components,  until,  finally,  the  sensations  pro- 
duced by  the  beating  of  the  heart,  remain  alone  to  constitute  the 
conscious  self  :  showing  in  the  first  place,  that  the  conscious  self 
at  any  moment  is  really  compounded  of  all  the  states  of  conscious- 
ness, presentative  and  representative,  then  existing  (§  219),  and 
showing  in  the  second  place,  that  it  admits  of  being  simplified 
so  far  as  to  lose  most  of  the  elements  composing  the  consciousness 
of  corporeal  existence.  Whence  it  is  inferable  that  self-conscious- 
ness begins  as  a  mere  rudiment  consisting  of  present  sensations, 
without  past  or  future.  Lastly,  we  have  the  striking  testimony 
that  there  exists  a  form  of  consciousness  lower  than  that  which 
the  lowest  kind  of  thought  shows  us.  The  simplest  intellectual 
act  implies  the  knowing  something  as  such  or  such — implies  the 
consciousness  of  it  as  like  something  previously  experienced,  or, 
otherwise,  as  belonging  to  a  certain  class  of  experiences.  But  we 
here  get  evidence  of  a  stage  so  low  that  a  received  impression 
remains  in  consciousness  unclassed :  there  is  a  passive  reception 
of  it,  and  an  absence  of  the  activity  required  to  know  it  as  such 
or  such. 


APPENDIX  a  641 


NOTE  TO  CHAPTER  VIII.   OF  PART  IV. 

In  his  Principles  of  Mental  Physiology,  Dr.  Carpenter,  refer- 
ring to  the  doctrine  of  mental  evolution  as  caused  by  the  inherited 
effects  of  experiences,  developed  in  the  foregoing  chapters,  says : — 

"  But  it  has  been  distinctly  foreshadowed  as  regards  the  Instincts  of  animals 
(which  are  only  lower  forms  of  Man's  intellectual  Intuitions)  by  Sir  John 
Sebright,  Mr.  T.  A.  Knight,  and  M.  Roulin ;  of  whose  observations  a  summary 
has  been  given  by  the  Writer  in  the  Contemporary  Review,  January,  1878. 
*  *  *  And  in  the  Fourth  and  Fifth  Editions  of  his  'Human  Physiology,* 
published  respectively  in  1862  and  1866,  the  Writer  had  distinctly  expressed 
his  belief  that  the  Cerebrum  of  Man  grows  to  the  modes  of  thought  in  which 
it  is  habiluallg  exercised;  and  tliat  such  modifications  in  its  structure  are 
transmissible  hereditarily.  *  *  *  He  here  refers  to  this  fact,  merely  to  show 
that  the  general  doctrine  above  enunciated  *  *  *  is  much  older  than  Mr. 
Herbert  Spencer." 

Communications  to  which  the  above  passage  led,  disclosed  the 
fact  that  Dr.  Carpenter  had  not  read  this  work ;  but  had,  as  I 
understood,  purposely  refrained  from  doing  so.  I  pointed  out  to 
him  the  difference  between  the  proposition  that  transmitted  mental 
modifications  produce  varieties  of  mental  faculty  within  the  limits 
of  a  species  ;  and  the  proposition  that  Mind,  in  all  its  faculties,  is 
produced  by  transmissions  of  such  modifications  through  all  the 
successions  of  species  during  the  evolution  of  life  upon  the  Earth. 
After  obtaining  from  Dr.  Carpenter  the  admission  that  this  latter 
proposition  had  not  even  been  entertained  (much  less  elaborated 
into  a  system)  by  those  he  names,  J  concluded  that  he  would,  in 
his  next  edition,  alter  the  above  statement.  He  has  not  done 
this,  however  ;  and  therefore,  somewhat  reluctantly,  I  must  myself 
point  out  the  grave  misrepresentations  it  embodies. 

Manifestly  no  one  can  entertain  the  belief  that  the  pscyhical 
powers  of  all  creatures  have  arisen  by  evolution,  without  tacitly  or 
avowedly  committing  himself  to  the  belief  that  their  physical  struc- 
tures ha\'e  arisen  by  evolution.  Dr.  Carpenter  is  fully  aware  that 
in  1855,  when  the  first  edition  of  this  work  was  published,  the 
"  development-hypothesis,"  as  it  was  then  commonly  called,  was 
repudiated  by  men  of  science,  as  well  as  by  the  world  at  large ; 
and  further,  that  any  one  who  held  it  exposed  himself  to  the  ridicule 
of  the  scientific.  He  does  not  allege  that  those  he  names  believed  it ; 
much  less  gave  a  public  adhesion  to  it.  Yet  now,  in  the  above 
passage,  he  asserts  that  he  and  others  had  enunciated  in  a  general 


APPENDIX  B. 

way,  the  doctrine  elaborated  in  this  work  :  they  avowed  a  conclu- 
sion the  necessary  premises  of  which  they  did  not  admit ! 

Either  Dr.  Carpenter  is  still  in  the  position  of  not  having  read 
this  work,  or  he  has  read  it  since  the  time  above  referred  to.  If  he 
has  not  read  it,  then  it  is  strange  that  he  should  undertake  to 
correct  the  impressions  of  "younger  readers,"  concerning  the 
relation  between  its  views  and  the  views  previously  held  (see 
Contemporary  Review,  for  February,  1875).  If  he  has  read  it,  then 
it  is  even  more  strange  that  he  should  persist  in  the  above  state- 
ment. In  the  first  place,  he  must  have  become  aware  that  the  facts 
and  inferences  named  by  him,  as  current  before  this  work  was 
written,  are  referred  to  in  this  work  as  familiar — are  taken  as 
established  (§  180,  in  edition  of  1856);  not  propounded  as  new. 
In  the  second  place,  he  must  have  seen  that  these  facts  and  infer- 
ences are  used  as  part  of  my  data — that  my  reasonings  begin 
where  the  reasonings  he  names  leave  off.  And  yet  having  seen 
this,  he  identifies  the  theory  that  mental  modifications  within  the 
limits  of  a  species  are  producible  by  inherited  effects  of  experiences, 
with  the  theory  that  the  genesis  of  all  mental  faculties,  down 
to  forms  of  thought,  have  been  thus  produced.  He  alleges  pre- 
vious currency  of  the  "  general  doctrine."  It  seems  to  me  that 
his  ideas  of  general  and  special  are  no  less  remarkable  than  his  idea 
of  identity.  The  proposition  that  such  changes  of  dog-nature  as 
a  pointer's  habits  show,  arise  by  inherited  mental  modifications, 
would  commonly  be  thought  a  special  proposition ;  while  the 
proposition  that  by  inherited  modifications  there  has  been  an  evol- 
ution of  Mind  in  all  its  modes,  from  reflex  action  up  to  abstract 
reason  and  moral  sentiment,  would  commonly  be  thought  a  general 
proposition.  But  Dr.  Carpenter  thinks  the  contrary.  Doubtless, 
in  pursuance  of  the  same  view,  he  regards  the  doctrine  that  pigeons 
and  other  domestic  animals  may  have  their  structures  modified  by 
selection,  as  a  "  general "  one ;  and  the  doctrine  of  Mr.  Darwin, 
that  all  structures  of  all  animals  are  caused  by  natural  selection, 
as  a  special  one.  For  the  two  cases  are  perfectly  similar.  Between 
the  idea  that  structural  changes  are  producible  within  the  limits  of 
a  species  by  selection,  and  the  idea  that  all  organization  is  thus 
producible,  there  is  a  relation  exactly  parallel  to  the  relation  be- 
tween the  idea  that  the  instincts  of  a  species  may  be  changed  by 
inherited  effects  of  experiences,  and  the  idea  that  all  mental  or- 
ganization is  producible  by  the  inherited  effects  of  experiences. 

Hence,  we  may  expect  that  when  next  Dr.  Carpenter  refers  to 
the  hypothesis  of  "  natural  selection,"  he  will  point  out  that  it  had 
been  distinctly  foreshadowed  by  Sir  John  Sebright,  Mr.  Youatt,  and 
others ;  and  after  quoting  passages  from  their  writings,  will  remark 
that  he  does  so  "  merely  to  show  that  the  general  doctrine  "  "  is 
much  older  than  "  Mr.  Darwin. 

(8) 


I 


''Destined  to  take  rank  as  one  of  the  two  or  three 
most  remarkable  self-portrayals  of  a  human  life  ever 
committed  to  posterity." 

— Franklin  H,  Giddings,  LL,D,,  in  the  Independent, 


An  Autobiography  by  Herbert  Spencer. 

With  Illustrations.  Many  of  them  from  the 
Author's  Own  Drawings.  Cloth,  8vo.  Gilt  Top. 
Two  vols,  in  a  box,  $5.50  net.  Postage,  40  cents 
additional. 

"  It  is  rarCj  indeed,  that  a  man  who  has  so  profoundly  influenced  the 
intellectual  development  of  his  age  and  generation  has  found  time  to 
record  the  history  of  his  own  life.  And  this  Mr.  Spencer  has  done  so 
simply,  so  frankly,  and  with  such  obvious  truth,  that  it  is  not  surprising 
that  Huxley  is  reported  as  having  said,  after  reading  it  in  manuscript, 
that  it  reminded  him  of  the  '  Confessions '  of  Rousseau,  freed  from  every 
objectionable  taint." — New  York  Globe. 

"  As  interesting  as  fiction  ?  There  never  was  a  novel  so  interesting 
as  Herbert  Spencer  s  'An  Autobiography  '."^—New  York  Herald. 

"  It  is  rich  in  suggestion  and  observation,  of  wide  significance  and 
appeal  in  the  sincerity,  the  frankness,  the  lovableness  of  its  human  note." 

— New  York  Mail  and  Express. 

"  The  book,  as  a  whole,  makes  Spencer's  personality  a  reality  for 
us,  where  heretofore  it  has  been  vaguer  than  his  philosophical  abstrac- 
tions."—^<»A«  White  Chadwick  in  Current  Literature. 

"  In  all  the  literature  of  its  class  there  is  nothing  like  it.  It  bears 
the  same  relationship  to  autobiographical  productions  as  Boswell's  '  Life 
of  Johnson  '  bears  to  biographies." — Philadelphia  Press. 

"  This  book  will  always  be  of  importance,  for  Herbert  Spencer  was 

a  great  and  original  thinker,  and  his  system  of  philosophy  has  bent  the 

thought  of  a  generation,  and  will  keep  a  position  of  commanding  interest." 

— Joseph  O'Connor  in  the  New  York  Timts. 

"  Planned  and  wrought  for  the  purpose  of  tracing  the  events  of  his 
life  and  the  growth  of  his  opinions,  his  autobiography  does  more  than 
that.  It  furnished  us,  half  unconsciously,  no  doubt,  a  more  vivid  por- 
traiture of  his  peculiarities  than  any  outsider  could  possibly  provide. 
We  pity  his  official  biographer!  Little  can  be  left  for  him.  Here  we 
have  Spencer  in  habit  as  he  was." — New  York  Evening  Post. 

D.    APPLETON     AND     COMPANY,    NEW     YORK. 


New  Edition  of  Professor  Huxley's  Essays. 

Collected  Essays. 

By  Thomas  H.  Huxley.  New  complete 
edition,  with  revisions,  the  Essays  being 
grouped  according  to  general  subject.  In 
nine  volumes,  a  new  Introduction  accom- 
panying each  volume.  i2mo.  Cloth,  J  1. 25 
per  volume. 

Vol. 

I.  Methods  and  Results. 
II.  Darwiniana. 

III.  Science  and  Education. 

IV.  Science  and  Hebrew  Tradition. 
V.  Science  and  Christian  Tradition. 

VI.  Hume. 

VII.  Man's  Place  in  Nature. 
VIII.  Discourses,  Biological  and  Geologfical. 
IX.  Evolution  and  Ethics,  and  Other  Essays. 

**  Mr.  Huxley  has  covered  a  vaat  variety  of  topics  during 
the  last  quarter  of  a  century.  It  gives  one  an  agreeable  surprise 
to  look  over  the  tables  of  contents  and  note  the  immense  territory 
which  he  has  explored.  To  read  these  books  carefully  and 
itudiouily  is  to  become  thoroughly  acquainted  with  the  most 
advanced  thought  on  a  large  number  of  topics." — titw  T^rk 
Herald. 

D.     APPLETON     AND      COMPANY,     NEW     YORK. 


HERBERT   SPENCER'S   WORKS. 

Estays:  Scientific,  Political,  and  Speculatire. 

A    New    Edition,   uniform   with   Mr.   Spencer's   other 

Works,   including  Seven   New    Essays.      Three    Yolumei. 

i2mo.     1,460  pages,  with  full  Subject  Index  of  34  pages. 

Cloth,  $6.00. 

These  essays  are  deroted  to  the  entire  range  of  subjects  covered  in 
Mr.  Spencer's  numerous  works,  and  embrace  the  social  and  political 
sciences,  education,  and  many  other  pertinent  topics  of  general  interest. 

Descriptive  Sociolos:y. 

A  Cyclopaedia  of  Social  Facts.  Representing  the  Con- 
stitution of  Every  Type  and  Grade  of  Human  Society,  Past 
and  Present,  Stationary  and  Progressive.  Eight  numbers, 
royal  folio. 

No.     I.  ENGLISH    I4  00 

II.    MEXICANS,     CENTRAL     AMERICANS,    CHIB- 

CHAS,  AND  PERUVIANS 4  00 

IIL   LOWEST      RACES,      NEGRITO      RACES,      AND 

MALAYO-POLYNESIAN    RACES 4  00 

IV.   AFRICAN   RACES  400 

V.   ASIATIC   RACES 400 

VL  AMERICAN   RACES 400 

VIL   HEBREWS   and   PHCENICIANS  400 

VIIL  FRENCH   (Double  Number) 700 

The  Induction  of  Ethics. 

The  Ethics  of  Individual  Life,  Parts  II  and  III  of  The 
Principles  of  Ethics.     One  volume.     lamo.     Cloth,  $1.25. 

Philosophy  of  Style. 

ismo.     Flexible  cloth,  50  cents. 

P.    APPLETON    AND    COMPANY,    NEW    YORK. 


PIONEERS  OF  CREATIVE  THOUGHT. 


Pioneers  of  Science  in  America. 

Sketches  of  their  Lives  and  Scientific  Work.  Edited  and 
revised  by  William  Jay  Youmans^  M.  D.  With  Portraits. 
8vo.     Cloth,  $4.00. 

"  a  wonderfully  interesting  volume.  Many  x  young  man  will  find  it  fascinating. 
The  compilation  of  the  book  is  a  work  well  done,  weU  worth  the  doine." — Philip 
dt^kta  Prttt. 

"  One  of  the  most  valuable  contributions  to  American  literature  recently  made. 
.  .  .  No  better  or  more  inspiring  reading  could  be  placed  in  the  hands  of  an  intelli- 
^nt  and  aspiring  young  man." — Winp  rork  Chrutian  Work. 

"A  valuable  handbook  for  those  whose  work  runs  on  these  same  lines,  and  is 
likely  to  prove  of  lasting  interest  to  those  for  whom  *  Itt  dccumtnU  humatH '  arc 
•econd  only  to  history  in  importance — nay,  are  a  vital  part  of  history." — Bcttcn 
Triuucript. 

"  It  is  certainly  a  useful  and  convenient  volume,  and  readable  too,  if  we  judge 
correctly  of  the  accuracy  of  the  whole  by  critical  examination  of  those  cases  in 
which  our  own  knowledge  enables  us  to  form  an  opinion.  ...  In  general,  it  seems 
to  us  that  the  handy  volume  is  specially  to  be  commended  for  setting  in  just  his* 
torical  perspective  many  of  the  earlier  scientists  who  are  neither  very  generally  nor 
very  well  known." — Nrw  York  Evening  Post, 


Pioneers  of  Evolution,  from  Thales  to  Huxley. 

By  Edward  Clodd,  President  of  the  Folk-Lore  So- 
ciety ;  Author  of  "  The  Story  of  Creation,"  **  The  Story  of 
'Primitive 'Man," etc.  With  Portraits.  lamo.  Cloth, $1.50. 

"  Luminous,  lucid,  orderly,  and  temperate.  Above  all,  it  is  entirely  free  from 
personal  partizanship." — London  AccuUmy. 

"  A  very  useful  guide  to  the  lives  and  labors  of  leading  evolutionists  of  the  past 
and  present.  Especially  serviceable  is  the  account  of  Mr.  Herbert  Spencer  and  his 
■hare  in  rediscovering  evolution,  and  illustrating  its  relations  to  the  whole  field  of 
human  knowledge." — London  Literary  World. 

"  The  mass  of  interesting  material  which  Mr.  Clodd  has  got  together  and  woven 
Into  a  symmetrical  story  of  the  progress  from_  ignorance  and  theory  to  knowledge 
and  the  intelligent  recording  of  fact  is  prodigious.  .  .  .  An  important  contribution 
to  a  liberal  education." — Lmtdon  Daily  Chronicle. 

"  We  are  always  glad  to  meet  Mr.  Clodd.  He  is  never  dull ;  he  is  always  well 
informed,  and  he  says  what  he  has  to  say  with  clearness  and  precision.  .  .  .  The 
interest  intensifies  as  Mr.  Clodd  attempts  to  show  the  part  really  played  in  the 

growth  of  the  doctrine  of  evolution  by  men  like  Wallace,  Darwin,  Huxley,  and 
pencer.  .  .  .  We  commend  the  book  to  those  who  want  to  know  what  evolution 
really  meant." — London  Timet. 

D. APPLETON    AND    COMPANY,     NEW    YORK. 


SPENCER'S  MISCELLANEOUS  WORKS. 


Social  Statics. 

New  and  revised  edition,  including  "  The  Man  versus  The  State." 
A  series  of  essays  on  political  tendencies,  heretofore  published  sep- 
arately.    i2mo,  420  pages.     Cloth,  $2.00. 

"  Mr.  Spencer  has  thoroughly  studied  the  issues  which  are  behind  the  social  and 
political  life  of  our  own  time,  not  exactly  those  issues  which  are  discussed  in  Parlia- 
ment or  in  Congress,  but  the  principles  of  all  modern  government,  which  are  slowly 
changing  in  response  to  the  broader  industrial  and  general  development  of  human 
experience.  One  will  obtain  no  suggestions  out  of  his  book  for  guiding  a  political 
party  or  carrying  a  point  in  economics,  but  he  will  find  the  principles  of  sociology, 
as  they  pertain  to  the  whole  of  life,  better  stated  in  these  pages  than  he  can  find  them 
expressed  anywhere  else.  It  is  in  this  sense  that  this  work  is  important  and  fresh 
and  vitalizing.     It  goes  constantly  to  the  foundation  of  things." — Boston  Herald. 

Facts  and  Comments. 

Uniform  edition.  i2mo.  Cloth,  $1.20  net ;  postage,  I3  cents  addi- 
tional. 

From  the  analytical  brain  of  a  philosopher  of  the  greatness  of  Herbert  Spencer — 
a  greatness  that  has  extended  over  more  than  two  generations — the  subjects  treated 
in  this,  his  last  volume,  assume  a  commanding  importance.  Such  topics  as  "  Ameri- 
canisms," "Presence  of  Mind,"  "The  Corruption  of  Music,"  "The  Origin  and  De- 
velopment of  Music,"  "Estimates  of  Men,"  "State  Education,"  etc.,  are  invested 
with  a  life  and  actuality  only  possible  under  his  stimulating  treatment. 

Various  Fragments. 

i2mo.     Cloth,  $1.25. 

Along  with  a  considerable  variety  of  other  matter,  these  "  Fragments  "  include  a 
number  of  replies  to  criticisms,  among  which  will  be  found  some  of  the  best  speci- 
mens of  Mr.  Spencer's  controversial  writings,  notably  his  letter  to  the  London  Atht- 
naum  on  Professor  Huxley's  famous  address  on  Evolutionary  Ethics.  His  views  on 
copyright,  national  and  international,  "  Social  Evolution  and  Social  Duty,"  and 
"Anglo-American  Arbitration,"  also  form  a  part  of  the  contents. 

Education :  Intellectual,  Moral,  and  Physical. 

i2mo.     Cloth,  $1.25  ;  paper,  50  cents. 
Contents. — What  Knowledge  is  of  most  Worth  ?    Intellectual  Education.    Mora) 
Education.     Physical  Education. 

The  Study  of  Sociology. 

(The  fifth  volume  in  the  International  Scientific  Series.)  l2mo. 
Cloth,  $1.50. 

Contents. — Our  Need  of  it.  Is  there  a  Social  Science  ?  Nature  of  the  Social 
Science.  Difficulties  of  the  Social  Science.  Objective  Difficulties.  Subjective  Diffi- 
culties, Intellectual.  Subjective  Difficulties,  Emotional.  The  Educational  Bias. 
The  Bias  of  Patriotism.  The  Class  Bias.  The  Political  Bias.  The  Theological 
Bias.    Discipline.    Preparation  in  Biolog^y.    Preparation  in  Psychology.    Conclusion. 

D.     APPLETON    AND     COMPANY,     NEW    YORK. 


BOOKS   BY   JOHN   TYNDALL,  LL.D^  F.RS. 

Essays  on  the   Floating  Matter  of  the  Air  in 
Relation  to  Putrefaction  and  Infection. 

Illustnitions.     lamo.     Cloth,  $1.50. 

Forms  of  Water  in  Clouds  and  Rivers,  Ice  and 
Glaciers. 

(International  Scientific  Series.)    i2mo.     Cloth,  $1.50. 

Heat  as  a  Mode  of  Motion. 

New  edition.     lamo.     Cloth,  $2.5a 

Sound. 

lamo.     Cloth,  I2.00. 

Fragments  of  Science  for  Unscientific  People. 

A  Series  of   Detached  Essays,   Lectures,  and  Reviews.     Revised  and 
enlarged  edition.     i2mo.     Cloth,  (2.00. 

Light  and  Electricity. 

Notes  of  Two  Courses  of  Lectures  before  the  Royal  Institution  of  Great 
Britain.     z2mo.     Cloth,  $1.35. 

Lessons  in  Electricity,  Royal  Institution,  i875-'76. 

i2mo.     Cloth,  $1.00. 

Hours  of  Exerciee  in  the  Alps. 

With  Illustrations.     12010.     Cloth,  $2.00. 

Faraday  as  a  Discoverer. 

A  Memoir.     lamo.     Cloth,  (i.oo. 

Contributions    to     Molecular     Physics     in    the 
Domain  of  Radiant  Heat. 

Memoirs  published  in  the  "Philosophical  Transactions "  ana  "  PhQO' 
Bophical  Magazine."     With  additions.    8vo.    $5.00. 

Six  Lectures  on  Light. 

Delivered  in  America  in  i872-'73.     i2mo.     Cloth,  $1.50. 

Address  delivered  before  the  British  Association         m 
assembled  at  Belfast.  M 

Revised.     i2mo.     Paper,  50  cents. 

Researches  on  Diamagnetism  and  Magne-CryS' 
tallic  Action. 

Including  the  Question  of  Diamacnetk  Polarity,     zo  Plates.     laino. 
Cloth,  $1.50. 

New  Fragments. 

i2fno.     Cloth,  fa.oo. 
D.    APPLETON     AND     COMPANY,    NEW    YORK- 


THE  PERENNIAL  CONFLICT. 
The  Warfare  of  Science  with  Theology. 

A  History  of  the  Warfare  of  Science  with  Theology  in 
Christendom.  By  Andrew  Dickson  White,  LL.  D.  (Yale), 
L.  H.  D.  (Col.),  Ph.  D.  (Jena),  late  President  and  Professor 
of  History  at  Cornell  University.   2  vols.  8vo.  Cloth,  $5.00. 

"  Able,  scholarly,  critical,  impartial  in  tone  and  exhaustive  in  treat- 
ment."— Boston  Advertiser. 

"The  most  valuable  contribution  that  has  yet  been  made  to  the 
history  of  the  conflicts  between  the  theologists  and  the  scientists." — 
Buffalo  Commercial. 

"  A  work  which  constitutes  in  many  ways  the  most  instructive  review 
that  has  ever  been  written  of  the  evolution  of  human  knowledge  in  its 
conflict  with  dogmatic  belief." — Boston  Beacon. 

"  The  same  liberal  spirit  that  marked  his  public  life  is  seen  in  the 
pages  of  his  book,  giving  it  a  zest  and  interest  that  can  not  fail  to  secure 
for  it  hearty  commendation  and  honest  praise." — Philadelphia  Public 
Ledger. 

"  Such  an  honest  and  thorough  treatment  of  the  subject  in  all  its 
bearings  that  it  will  carry  weight  and  be  accepted  as  an  authority 
in  tracing  the  process  by  which  the  scientific  method  has  come  to  be 
supreme  in  modem  thought  and  life." — Boston  Herald. 

"  The  story  of  the  struggle  of  searchers  after  truth  with  the  organ- 
ized forces  of  ignorance,  bigotry,  and  superstition  is  the  most  inspiring 
chapter  in  the  whole  history  of  mankind.  That  story  has  never  been 
better  told  than  by  the  ex-President  of  Cornell  University  in  these  two 
volumes." — London  Daily  Chronicle. 

"  It  is  graphic,  lucid,  even-tempered — never  bitter  nor  vindictive. 
No  student  of  human  progress  should  fail  to  read  these  volumes. 
While  they  have  about  them  the  fascination  of  a  well-told  tale,  they 
are  also  crowded  with  the  facts  of  history  that  have  had  a  tremendous 
bearing  upon  the  development  of  the  race." — Brooklyn  EagU. 

D.  APPLETON  AND  COMPANY,  NEW  YORK. 


BY  EMINENT  SQENTISTS. 


Foot-Notes  to  Evolution. 

A  Series  of  Popular  Addresses  on  the  Evolution  of  Life.  By 
David  Starr  Jordan,  Ph.D.,  President  of  Leland  Stanford  Junior 
University.     i2mo.     Cloth,  $1.50. 

This  book  is  a  popular  review  of  the  evolution  philosophy  of  to-day,  con- 
sidered more  especially  in  its  biological  aspects.  The  essential  unity  of  all 
organisms,  both  plant  and  animal,  the  fact  that  progress  in  life  consists  solely 
of  adaptation  to  environment,  and  the  relation  of  heredity  and  degeneration  to 
the  evolutional  scheme,  are  among  the  points  of  special  interest. 

Outlines  of  the  Earth's  History. 

By  Prof.  N.  S.  Shalkr,  of  Harvard  University.  Illustrated.  lamo. 
Cloth,  f  1.75. 

The  object  of  this  book  is  to  provide  the  banner  in  the  study  of  the  earth's 
history  with  a  general  account  of  those  actions  which  can  be  readily  understood 
and  which  will  afford  him  clear  understanding  as  to  the  nature  of  Uie  processes 
which  have  made  this  and  other  celestial  spheres. 

The  Psycholog^y  of  Suggestion. 

A  Research  into  the  Subconscious  Nature  of  Man  and  Society.  By 
Boris  Sidis,  M.A.,  Ph.D.,  Associate  in  Psychology  at  the  PathologiciJ 
Institute  of  the  New  York  State  Hospitals.  With  an  Introduction  by 
Pro£  William  James,  of  Harvard  University.     Cloth,  $1.75. 

The  book  is  an  original  investigation  into  the  nature  of  suggestion  and  into 
the  subconscious  mechanism  of  the  human  mind.  The  subconscious  nature  of 
man's  psychic  life  is  closely  examined,  and  a  theory  of  the  constitution  and 
activity  of  the  mind  is  worked  out.  The  theory  of  the  subconscious  is  used  to 
elucidate  many  important  pathological  phenomena  of  individual  and  social 
life.  Mental  epidemics  are  traced  to  their  source,  cmd  their  causes  and  nature 
of  operation  cire  examined  and  explained. 

Evolutional  Ethics  and  Animal  Psychology. 

By  E.  P.  Evans.     Cloth,  $1.75. 

Contents.— The  Ethics  of  Tribal  Society.  Religious  Belief  as  a  Basis  of 
Moral  Obligation.  Ethical  Relations  of  Man  to  Beast.  Metempsychosis. 
Mind  in  Man  and  Brute.  Progress  and  Perfectibility  in  the  Lower  Animals. 
Ideation  in  Animals  and  Men.  Speech  as  a  Barrier  between  Man  and  Beast. 
The  iCstbetic  Sense  and  Religious  Sentiment  in  Animals.  Bibliography. 
Index. 

D.    APPLETON    AND    COMPANY,    NEW    YORK. 


I  tor 

0-' 


SOUTHErSI  RpSf.'  ?="*«"» 


^^^^aZ^^ 


iiiiir 

A  A      000  079  360  4 


